Resources / Faraday Technology
The physics of signal isolation.
Every wireless signal, from phone signals to GPS, WiFi, 5G and Bluetooth, is electromagnetic radiation (EMR) - energy that travels through space in the form of oscillating electric and magnetic waves. A Faraday enclosure is the only hardware-level guarantee of EMR isolation.
The Fundamentals
Everything wireless is
electromagnetic radiation.
Visible light, heat from the sun, a phone call, a GPS fix, an RFID tap. All create the same fundamental phenomenon: oscillating electric and magnetic fields propagating through space at the speed of light.
What separates them is frequency: how many times per second the wave oscillates. Low frequency means long wavelength and low energy. High frequency means short wavelength and high energy. The full range, from the lowest radio waves to gamma rays, is the electromagnetic spectrum.
The portion relevant to wireless communications, from around 3kHz to 300GHz, is called the radio frequency (RF) band. Every signal your device sends or receives lives somewhere in this band. A Faraday enclosure that blocks within this entire band blocks all of them, simultaneously, with no power source required and no failure mode.
Non-ionising vs ionising radiation
RF signals sit in the non-ionising band of the electromagnetic spectrum. That's a different regime to X-rays and gamma rays, which carry enough photon energy to strip electrons from atoms and damage cells.
Faraday enclosures block RF at the physics level. Ionising radiation needs different shielding (typically lead) and is a separate concern outside what Faraday products address.
The Spectrum
Where wireless lives, and what we block.
Radio frequency (RF) signals span the frequency range from 3kHz to 40GHz. Every cellular, Wi-Fi, GPS, Bluetooth, and IoT signal falls within that range. A Faraday enclosure that offers 90dB attenuation blocks all of those signals, simultaneously.
Signals blocked by a 90dB Faraday enclosure
| Signal type | Frequency range | What uses it | Threat relevance |
|---|---|---|---|
| RFID / NFC | 125kHz – 13.56MHz | Contactless payments, access cards, asset tags, passport chips | Skimming, cloning, unauthorised access |
| GPS / GNSS | 1.176 – 1.602GHz | Location tracking, navigation, timestamping | Device location tracking, movement surveillance |
| Bluetooth | 2.4GHz | Peripherals, audio, AirTags/Find My, proximity beacons | Location tracking, device fingerprinting |
| Wi-Fi | 2.4GHz / 5GHz / 6GHz | Data networks, smart home devices, cloud sync | Remote access, data exfiltration, network attacks |
| 4G LTE | 700MHz – 2.6GHz | Mobile voice and data, SMS | Calls/messages, IMSI catchers, remote commands |
| 5G | 600MHz – 40GHz | High-speed mobile, IoT, fixed wireless | High-bandwidth data transfer, dense tracking |
| EMP / HEMP | DC – multi-GHz pulse | Natural or weapons-generated electromagnetic pulses | Permanent destruction of unshielded electronics |
The Mechanism
Why the physics is impossible to override.
Faraday enclosures don’t jam signals, scramble frequencies, or run software. They use the fundamental properties of conductive materials to create a zone where electromagnetic fields mathematically cannot exist.
For the layperson
The cancel-out principle
When an electromagnetic wave strikes a conductive material, the wave’s energy forces the free electrons in the metal to move. Those moving electrons generate their own electromagnetic field, one that exactly opposes the incoming wave. The two fields cancel each other out. Inside the enclosure, the net field is zero. No field means no signal.
For the technically curious
Gauss’s Law & Material Thickness
The incoming wave forces free electrons in the conductor to redistribute, creating an opposing field per Gauss’s Law. Simultaneously, eddy currents produce a counteracting magnetic field. At 40GHz, the thickness of the metallic fabric is just microns, which is why thin TitanRF™ fabric achieves >90dB without requiring bulk.
This is physics, not just technology. There is no firmware to exploit, no setting to override, no battery to drain. A device inside a properly sealed Faraday enclosure is electromagnetically isolated by the laws of physics, the same laws that have held since Michael Faraday demonstrated them in 1836.
Shielding Effectiveness
What 90dB actually means in practice.
Every Faraday product claims to have a dB rating, yet most people have no understanding of what that rating means. The decibel is a logarithmic unit, the scale is not linear, and the numbers are vastly more dramatic than they appear.
Each 10dB of attenuation reduces signal power by a factor of 10. This means 20dB doesn’t double 10dB’s protection, it multiplies it by 10. By the time you reach 90dB, you are reducing the incident signal to one-billionth of its original power.
No cellular tower, GPS satellite, or Bluetooth scanner on Earth can communicate with a device at that attenuation level. This is why 90dB is cited in military and law enforcement specifications; it’s the threshold at which isolation is operationally absolute.
Why logarithmic?The power differences involved in wireless communications span billions of orders of magnitude. A linear scale would be unworkable, writing “99.9999999% blocked” is cumbersome. Decibels compress that range into manageable numbers.
The same logarithmic unit is used to measure sound (a rock concert is about 110dB louder than the threshold of hearing). In shielding, higher is better; in acoustics, it’s the opposite, but the mathematics are identical.
Why Distance Changes Everything
80dB might be enough at 1km. It may not be enough at 100m.
Signal power follows the inverse square law: halve the distance to a tower and the power arriving at your device quadruples. This is not a linear relationship, it is exponential. A bag that provides adequate isolation in a rural environment with a single tower 2km away may be completely inadequate in a dense urban environment where 5G small cells are mounted every 200–300 meters at street level.
| Scenario | Distance | Signal at device | After 80dB bag | After 90dB bag | Verdict |
|---|---|---|---|---|---|
| Rural / suburban5G macro tower, 43 dBm | 1,000m | −59 dBm | −139 dBm | −149 dBm | Both adequate |
| Urban — city block5G macro tower, 43 dBm | 100m | −39 dBm | −119 dBm | −129 dBm | 80dB borderline 90dB isolated |
| Dense urban — small cell5G small cell, 24 dBm | 10m | −38 dBm | −118 dBm | −128 dBm | 80dB likely fails 90dB isolated |
The practical implication for New Zealand: 5G densification in cities, particularly Auckland, Wellington, and Christchurch, means the installation of street-level towers every 200 to 300 meters has become increasingly common. If verified isolation matters, for digital forensics, executive security, or operational use, the 10dB gap between 80dB and 90dB is the difference between “probably blocked” and “definitively blocked.” Mission Darkness and OffGrid Faraday products target 90dB+ attenuation. That’s why they are the preferred Faraday products for military, government and forensic agencies worldwide, including New Zealand.
When isolation matters
Three threats Faraday isolation is designed for.
These are the scenarios where hardware isolation is the only reliable countermeasure.
Location Tracking & Surveillance
A powered device is a broadcasting device. GPS satellites, cell towers, Bluetooth beacons and Wi-Fi access points triangulate location to within metres. Many devices keep low-level RF scanning active in airplane mode because the radio hardware never fully powers down. Only a Faraday enclosure guarantees isolation.
Remote Access & Data Exfiltration
Zero-click exploits like Pegasus compromise a device with no user interaction. Once installed, malware drives the microphone, camera and data exfiltration over any RF connection. MDM and antivirus can't block what they can't detect. Devices can be remotely wiped. Faraday shielding severs all signals: and no connection means no access.
EMP & HEMP Protection
Electromagnetic pulse events from high-altitude nuclear detonation, solar CME's, or directed energy weapons, generate a broadband pulse that permanently destroys unshielded electronics. Mission Darkness and OffGrid are verified to MIL-STD-188-125-2 by Keystone Compliance, the US military's HEMP shielding standard.
Independent Verification
Standards that make the numbers mean something.
To officially supply government, intelligence, and military agencies, Faraday products must undergo rigorous independent testing to specific electromagnetic shielding and hardening by an accredited third-party laboratory, in order to verify the dB rating and effectiveness. While everyday consumer pouches only need to block basic signals, mission-critical Faraday products require proven, quantifiable laboratory verification.
We have taken the position that everyday people should also have access to the premium Faraday products that high level organisations use.
Mission Darkness and OffGrid Faraday products have both been certified by Keystone Compliance to meet standards MIL STD 188-125 and IEEE 299-2006. That’s why we stock them, and why they are trusted worldwide. Keystone Compliance is an accredited regulatory compliance and testing laboratory based in the USA, with official recognition from the FCC and international regulatory bodies.
The measurement methodology
Published by the Institute of Electrical and Electronics Engineers, IEEE 299-2006 defines the precise methodology for measuring shielding effectiveness of enclosures. It specifies test setup, antenna placement, frequency sweep requirements, and how results must be reported.
When a product cites a dB rating against this standard, the number is directly comparable with any other IEEE 299-tested product. Without a named standard, dB claims are unmeasurable and unverifiable. Both Mission Darkness and OffGrid are tested to IEEE 299-2006 by Keystone Compliance.
The HEMP performance threshold
The United States Department of Defense specification for high-altitude electromagnetic pulse (HEMP) protection. MIL-STD-188-125 defines the shielding threshold required for systems protecting mission-critical DoD communications equipment from high-altitude nuclear pulse events.
Testing requires not just passive attenuation measurement but pulsed current injection, verifying the enclosure survives the leading edge of a HEMP pulse. Both Mission Darkness and OffGrid products exceed this threshold, independently verified by Keystone Compliance using the same test methodology.
Proprietary Fabric Technology
Two fabrics. One standard of proof.
Mission Darkness and OffGrid each developed their own proprietary shielding fabrics, independently tested by the same accredited Keystone Compliance laboratory, against the same standards. The brands have their own distinct approaches to solving the Faraday isolation problem, both verified to perform to military requirements.
TitanRF™ - Mission Darkness
90dB+ floor across the full spectrum
Mission Darkness's proprietary copper-nickel composite fabric, independently tested by Keystone Compliance to IEEE 299-2006. TitanRF™ achieves 80–100dB across the tested frequency range and the 90dB+ figure is a floor specification, the minimum guaranteed across the entire spectrum from 10kHz to 40GHz, not a peak or average.
The NeoLok™ patented magnetic closure (US11284546B2) is engineered for forensic chain-of-custody requirements. All Mission Darkness closure systems are designed to maintain RF integrity through repeated daily use, keeping evidence sealed and shielded across long field deployments.
Best for: Digital forensics, evidence integrity, military/defence deployment, EMP preparedness, applications requiring a verified floor specification.
Vega Wrap™ - OffGrid
103dB average in the critical band
OffGrid's proprietary nickel-copper fabric, independently tested by Keystone Compliance to IEEE 299-2006, and cross-referenced by the Wireless Research Center. The OffGrid Premium bag achieves 103dB average attenuation between 10MHz and 10GHz, the frequency band covering every major civilian and military communication protocol: cellular (2G–5G), Wi-Fi, Bluetooth, GPS, and RFID.
Thermo-welded seams eliminate the stitching penetrations that create signal leak points in conventional bags. Anti-abrasive inner shielding protects the device and fabric from daily wear.
Best for: Executive security, everyday carry, corporate deployment, personnel privacy, government procurement.
Not sure which suits your application? Talk to us and we'll recommend the right product.
Beyond The Spec Sheet
What the dB rating doesn’t tell you.
A shielding specification tells you what a Faraday product achieved in a laboratory on the day it was tested. It does not tell you how many layers the fabric uses, whether the seams are welded or stitched, or how the closure performs after six months of daily use. These are the questions that determine whether your bag actually works when you need it to.
The Layers Question
Verified fabric is what makes layering meaningful.
At RF frequencies above 1GHz, the thickness of a conductive metallic fabric is measured in microns. An electromagnetic wave is substantially attenuated in a single pass through high-quality fabric, because the material itself reaches saturation attenuation almost immediately.
Mission Darkness verifies TitanRF™ at Keystone Compliance. OffGrid verifies Vega Wrap™ at the Wireless Research Center. Both layer their verified fabric into bags that comfortably exceed the 90dB operational threshold. The fabric's verification carries through every layer of construction.
The Closure
The closure carries the conductive boundary.
A Faraday enclosure requires a complete, unbroken conductive boundary. The fabric is rarely the weak point; the closure is. Any gap in the closure seal allows the device to re-establish cellular or GPS connection within seconds.
Mission Darkness Dry Shield and OffGrid Premium use thermo-welded construction across the closure. The seam is bonded through the conductive fabric without stitch penetrations, so the conductive boundary remains continuous around the bag. Mission Darkness also offers the patented NeoLok™ magnetic closure for forensic chain-of-custody requirements. In both, the closure carries the shielding load.
Common Questions
Questions that come up regularly.
The information above outlines what Faraday technology is all about and how it works, but you might still have questions.
It depends on how "switched off" is defined and the device model. Many modern smartphones don't fully power down their radio hardware when the phone is turned off. Both "Apple Find My" and "Google Find My Device" networks use low-power Bluetooth and Wi-Fi to ping nearby devices, transmitting the phone's location even without power. A Faraday enclosure is the only way to guarantee phone "invisibility" regardless of the device's software state.
No. Location services is a software permission layer, not a hardware control. Disabling it prevents apps from formally requesting GPS data, but it doesn't stop the GPS receiver from operating, doesn't stop cell tower triangulation (which happens at the network level, not the device level), and doesn't affect Bluetooth or Wi-Fi positioning. Cell carriers can determine your approximate location from whichever tower your phone is connected to, regardless of software settings. Hardware-level RF isolation through a Faraday enclosure is what guarantees a device cannot be located.
Airplane mode reduces most RF activity, but it's a software instruction, not a hardware guarantee. Research has shown that certain device firmware, compromised OS states, and malware intrusions can bypass airplane mode and continue transmitting. Additionally, airplane mode typically doesn't disable the GPS receiver (GPS is receive-only and technically creates no interference, so many manufacturers leave it enabled). For operational security where guaranteed isolation is required, airplane mode cannot be relied upon. A Faraday enclosure operates at the physics level: the signal cannot propagate, regardless of the software state of the device inside.
Aluminium foil is a conductor and provides some RF attenuation, but it is inconsistent, highly frequency-dependent, and far below the 90dB+ attenuation achieved by military-grade Faraday fabric. Typical household foil provides perhaps 20–30dB at some frequencies under ideal conditions. More critically, gaps, folds, and imperfect sealing dramatically reduce effectiveness at the most important frequencies. A foil-wrapped phone might block some signals while ineffective for other signals. For casual privacy, foil can provide basic protection. For any application where verified signal isolation is required, it isn't suitable.
Any device that communicates wirelessly or that needs protection from electromagnetic pulses and solar flares: smartphones, tablets, laptops, USB & hard drives, key fobs, contactless cards and passports, GPS trackers, two-way radios, Crypto wallets, critical electronics and more.
Reduce your everyday EMF exposure.
Personal EMF protection from our carefully crafted range. EMF sensitivity products from Mission Darkness and OffGrid, air-tube headsets from iBrain. All tested to real-world standards, so you can trust what’s protecting you.