This is the largest bag in the MAS series — 29.5 × 13.5 × 26.0 inches outside, 25.0 × 12.0 × 23.5 inches inside, three RF shielding layers. It is sized for a portable generator, a radio set, a case of electronics or a full equipment kit, rather than for handsets.

Farday Generator Bag – MAS Series – 3 RF Layers

29.5 x 13.5 x 26.0″ (Outside), 25.0 x 12.0 x 23.5″ (Inside)

What a Faraday enclosure does, and what it does not

A Faraday bag is a conductive enclosure. Electromagnetic energy cannot cross it in either direction, so anything inside is isolated from signals and from radiated fields — that is physics, not a setting, and it works on equipment that is switched off and equipment you do not control.

It is worth being straight about the limits, because this category attracts a lot of overclaiming. Shielding effectiveness is a measured figure in decibels, not a binary. It depends on the layer count, on the integrity of the seams, and above all on the closure being sealed correctly every time — a partially closed bag is an aperture, and an aperture is how energy gets in. Contents touching the conductive layer can also couple energy across it, which is why padding or an inner non-conductive container matters for a tight fit.

Equally: a bag protects what is inside it. A generator in storage is protected; a generator that is running, fuelled and connected to a load is not in a bag. This is a preparedness item for a spare or a reserve kit, not something you operate equipment inside.

What people actually put in this size

A portable inverter generator or power station. A radio set with its antennas and spare batteries. A reserve laptop, tablet and phone kept off-network. Spare ECUs and control boards. A full field kit that would otherwise need four separate bags — which matters, because four closures are four chances to seal one wrong.

Do not overfill it. If the closure cannot fold and secure exactly as designed, the bag is not doing its job regardless of how many layers it has.

Storage discipline

Test it before you trust it: put a phone inside, close it properly, and call the phone. If it rings, the seal is wrong. Repeat that test periodically, because shielding degrades with flexing and abrasion — a bag opened daily is a different bag after a year than one opened twice.

For long-term storage, take lithium batteries to roughly half charge rather than full, keep the bag somewhere cool and dry, and label the contents on the outside so nobody opens it to check.

See the full Faraday bag range for phone, laptop and utility sizes, or talk to us about what belongs in a reserve kit.