Help & Support

Faraday bag care and testing

Faraday bags are consumable items, and the shielding integrity of the Faraday fabric inside a bag has a limited life. This guide covers how to test that a bag is working, how to care for it, and how to determine when it needs to be replaced.

How to close a bag properly before testing

The closure method depends on the product:

• Standard Velcro-closure bags (MD and OffGrid). Roll the top of the bag over on itself twice, then press the Velcro seal fully closed across the whole width.
• NeoLok bags. Position the device at the base of the sleeve so the top of the device sits well below the fold line. Fold the NeoLok flap over — the magnetic closure engages automatically. The device must sit low enough that the top of it doesn't obstruct the fold.

How to test a bag

A basic RF integrity test is quick and requires no special equipment:

• Place a mobile phone inside the bag, close it per the method above, and wait a few minutes.
• Use another phone to call the enclosed phone. The phone should not ring, vibrate, or give you a notification whilst enclosed in the bag.
• Repeat with a Wi-Fi test: attempt to transfer a file to the enclosed phone from a device outside the bag. A working bag blocks the transfer.
• Repeat with a Bluetooth device pairing attempt. A working bag prevents the pairing.

Important caveat on this test. The basic phone-signal test confirms shielding against ordinary consumer-cellular, Wi-Fi, and Bluetooth signals. It does not measure attenuation in dB, and it does not test performance against higher-power signal environments. Faraday bags degrade over time — shielding weakens against high-power signals first, and against ordinary signals later. A bag that still passes the basic test may already have reduced performance against 5G small cells at close range, or in dense urban RF environments. For agencies operating within high-power signal environments, factor this into replacement cycles and consider periodic quantitative testing with a signal-strength meter.

Cleaning

Never wash a Faraday bag or expose the Faraday fabric to water or moisture. The metal fibres in the shielding fabric (TitanRF, TitanRF Flex, Vega Wrap, and equivalents) oxidise on contact with water. Oxidation is permanent and destroys the shielding capability of the fabric.

To care for a bag: the outside shell of the Faraday bags can be cleaned with a slightly damp cloth, but the inside must be kept dry. Do not machine wash, hand wash, soak, damp-wipe, or use any liquid cleaner.

Faraday blankets, fabric, patches, and tape cannot be returned after opening, and there is no warranty once used. Bags that have been washed are not covered by warranty.

Use and Storage

• For the Faraday products that use Velcro closure systems, ensure that the inner Faraday fabric does not get caught in the Velcro, which could lead to abrasion of the Faraday fabric.
• Keep away from sharp objects, as punctures to the outer shell may compromise the Faraday fabric inside.
• Store the bag in a a dry environment and avoid direct sunlight for extended periods.
• Do not insert metal or sharp objects inside the bag, as this will damage the Faraday fabric inside. Ensure that covers for phones, laptops etc do not have rough or sharp edges.

Expected life and signs of degradation

The shielding effectiveness of all Faraday fabrics will degrade over time, based on frequency of use, environmental conditions, and care. We recommend that your Faraday product be evaluated regularly for wear and tear, for oxidation of the Faraday fabric, and for tears or punctures that might compromise the integrity of the shielding.

The following are what to look out for to determine if the bag needs replacing:

• Visible wear or fraying at closure points (Velcro edges, magnetic closure seals).
• Visible wear or fraying of the Faraday fabric.
• Small tears or punctures in the shielding fabric.
• Visible oxidation or discolouration on the Faraday fabric surface.
• The closure no longer seals fully.
• The bag fails the basic RF test described above.
• if your operational context has changed to a higher-power RF environment, you may need to replace your bag.

What not to do

• Never expose the Faraday fabric inside the Faraday bag to water..
• Do not cut, puncture, or modify the shielding fabric.
• Do not use a bag beyond the manufacturer's specified operational context.

Charge & Shield Bags

Charge & Shield bags maintain device power without breaking RF isolation. That matters in the field-to-lab evidence chain, where a device that dies in transit can lose volatile memory or trigger full-disk encryption on reboot. This guide covers how the pass-through works, what to plug in, and how to spot problems.

How the pass-through works

The bag has a shielded USB-C connector that routes power into the internal cavity without breaking the Faraday shielding around the device. The device stays fully isolated from RF signals while charging.

Standard configuration: USB-C power adapter → shielded pass-through cable → device inside the bag. Compatible with most USB-C power sources rated 5V/2A or higher. For tablets and larger devices, use a 3A minimum adapter for reliable charging under load.

Using with Blocker Locker or lab systems

Charge & Shield bags integrate with Mission Darkness Blocker Locker cabinets and with lab extraction workstations via the same pass-through cabling. Route the cable from the bag into the locker compartment's power feed, or directly to the extraction system's USB-C hub.

The OffGrid Premium Faraday Tablet Bag with Phase Filter uses a cable with a toggle switch built into the connector block. The switch selects between two modes: power-only (charging with no data path — for evidence storage) and data-enabled (power plus USB data — for controlled extraction sessions). The mode is set at the connector block, not on the bag.

Cables — user-supplied

Custodi does not supply the pass-through cables. Use any standard USB-C cable with the correct connector at the bag end. Cable length and quality is your choice — a shorter cable inside an evidence locker, a longer one for lab-bench routing. If a cable fails, replace it from any regular supplier.

Common failure modes

• Damaged cable at the bag exit. The shielding seal around the cable is a wear point. Inspect the cable jacket where it exits the bag before every use. Frayed jacket = compromised shielding.
• Dirt or debris in the USB-C port. Use canned air to clear the port gently. Do not insert metal tools.
• Closure not fully engaged around the cable exit. Test after closing by attempting a call or file transfer to the enclosed device. If the device receives, the closure has not sealed properly.
• Underpowered adapter. If the device drains faster than it charges, upgrade to a higher-amperage adapter.

Care and cleaning

• Never wash the bag or expose the Faraday fabric to water. Water causes permanent shielding loss through fibre oxidation.
• To clean: dust off, wipe with a dry microfibre cloth.
• Store the bag flat and store the cable coiled loosely, not tightly wound.
• Inspect the bag's pass-through port and the cable at every use, for any damage.

Blocker Locker setup

Mission Darkness Blocker Locker provides RF-shielded multi-device storage with continuous power. This guide covers the operational setup: siting, power routing, per-slot configuration, and chain-of-custody use. For physical installation steps refer to the MD Blocker Locker manual supplied with the unit.

Where to install

• Away from high-EMF sources. Server rooms, industrial equipment, high-power wireless infrastructure all elevate the baseline RF environment. Locate the locker in a normal office or evidence-room environment.
• Adequate ventilation for continuous-power operation. Ensure clearance per the manufacturer specification.
• Access control aligned to your evidence-management policy. The locker is physical security as well as RF security. Site it inside a controlled-access space.
• Follow the MD install manual for mounting, power connection, and any site-specific requirements.

What's in the locker

The Blocker Locker has 7 individual compartments, each with its own RF-shielded enclosure and its own charging feed. That's the configuration Custodi supplies — no smaller or larger variants.

Per-compartment configuration

• Assign each compartment to a specific device or case for chain of custody.
• Label externally per your evidence-management system (case number, device identifier, seizure date).
• Log entry and exit of each device against the compartment ID in your case-management platform.
• Do not co-store devices from different cases in the same compartment unless your evidence policy permits.

Power routing

• Each compartment has its own USB-C charging feed for keeping the device topped up during storage.
• Do not leave adapters unplugged with the compartment in use — a dead adapter defeats the purpose of a locker with continuous power.
• Verify each feed before committing a device: plug in a test phone, close the compartment, confirm the phone is charging and receives no RF.

Workflow — storage and charge, not extraction

The Blocker Locker is a storage and charge station. Devices sit in the locker between intake and active examination, staying charged and shielded through the wait. Extraction does not happen from inside the locker. When a device is due for examination, it comes out of the locker and moves to the extraction bench.

For the walk between locker and bench, keep the device inside a Faraday bag (Charge & Shield if power needs to be maintained, standard Faraday bag otherwise) so isolation is preserved during the transfer.

Chain-of-custody flow:

• Intake → assign a compartment → log entry → device stays charged and shielded
• When ready for examination → log removal → transport to extraction bench in a Faraday bag
• Post-examination → return to the compartment if the device is still in evidence hold, or move to the next stage of the evidence chain

Common issues

• Compartment door not fully sealed. Visual inspection after closing is the fastest check. Shielding depends on complete seal.
• Power supply failure. If devices are losing charge, isolate whether the fault is the wall adapter, the compartment feed, or the internal cable.
• Cable damage at compartment pinch points. Cables routed through compartment door areas can wear if pinched over time. Inspect regularly.

iBrain headset care

iBrain AirTube headsets use hollow air tubes to carry sound to the ears, with the drivers placed further down the cable. Rather than one continuous cable, AirTube headsets are constructed in two sections and as a result the headsets are inherently more fragile than wired headsets and should be treated with extra care when handling.

Cable care

The lower cable is made of shielded copper and carries the audio signal to the drivers. Damage to the cable jacket compromises the EMF shielding.

• Do not kink or fold the cable.
• Ensure that you don’t pull too hard on the headset when extracting from bags, drawers, pockets etc, as this may cause it to break and come apart.
• Store loosely coiled, not tightly wound.
• Inspect the cable regularly for wear, especially at strain points (the plug end and where the cable joins the ear tubes).
• Do not use if the cable jacket is visibly cut or the shielding is exposed.

Sound quality troubleshooting

• No sound in one ear. Check the tube connection at the driver housing, in case it has become disconnected internally.
• Intermittent sound. Usually cable damage. Wiggle the cable at the plug end and near the driver housing while a sound is playing to isolate the failure point.
• Loose ear-tip. Try a different size from the supplied pack. A poor seal reduces bass and audibility.