Mission Darkness key fob 2-pack review

What the maker says it does

Mission Darkness says malicious vehicle entry using key fob signal boosting is the leading threat in the automotive community, and describes criminals using amplification devices to boost or mimic a fob's signal. The page does not give a figure for how common this is, and we have not checked the claim against police data.

The pouch is meant to keep a fob from communicating with the car while it sits inside. The page says the bag shields always-on fobs and other small electronics, such as an Apple Watch, transmitters and credit cards, and that it also lets you keep a spare fob isolated and locked inside the vehicle. Our Faraday bag comparison lists larger bags.

Size and build

The maker lists the external size, closed, as 5 by 3.25 by 0.25 inches, and the internal usable size as 4.5 by 3 inches. It says the bag takes two fobs, or one fob plus key ring accessories, and that two bags come in each set.

The exterior is water-resistant ballistic nylon, with three layers of TitanRF Faraday Fabric on all interior sides and dual paired seam construction. It has a belt loop on the back and a key ring loop, and every bag carries a unique serial number.

Closing and using it

The closure is a fold-and-tuck: place the fob completely inside, fold the top over and tuck it under the elastic band. The maker says the fob should stay in the bag at all times when not in use, so the bag works as a home for your keys rather than a pocket liner.

That has an everyday cost: a sealed fob cannot unlock the car, so you take it out each time. If you only want it protected overnight, leave the bag by the door, and keep a spare key somewhere that does not rely on the fob's radio.

Signals and certification

The maker lists blocked signals as Wi-Fi at 2.4 and 5 GHz, Bluetooth, cell signals including 5G, GPS, RFID and NFC, and radio signals from low MHz to 40 GHz. It says the fabric is lab tested and certified to MIL STD 188-125 and IEEE 299-2006.

That is a certification for the fabric. Mission Darkness's phone bag page says full test reports are available on request. A fold-and-tuck closure has no roll-down seal, so the finished bag's performance is worth checking yourself.

How to check yours

The page gives no test procedure for a finished bag. For a car with a keyless-entry fob, a simple check is to put the fob in the sealed pouch and try the doors or the push-button start while standing next to the car. If the car responds, the pouch is not blocking it, so try again with the fob fully inside and the top folded and tucked.

Because we have not tested this product, treat that as a suggestion, and contact the maker if a bag does not block your fob. The bag also does nothing for a fob you carry in your pocket while driving.

Who should skip it

Skip it if you need to shield a full-size phone or a tablet: the internal space is 4.5 by 3 inches, and the maker lists only small phones among the things it is commonly used to shield. Skip it if you do not have a keyless-entry car or a worry about fob signals, and skip it if you want a bag you can drop in water, because the maker describes only a water-resistant exterior.

What size is the key fob bag?

Mission Darkness lists an internal usable size of 4.5 by 3 inches and an external closed size of 5 by 3.25 by 0.25 inches. It takes two fobs, or one fob plus key ring accessories.

How many bags come in the pack?

Two bags in each set, according to the maker's page. Each has a belt loop, a key ring loop and its own serial number.

How do I close the bag?

Place the fob completely inside, fold the top over and tuck it under the elastic band. The maker says the fob should stay inside the bag at all times when not in use.

Does it work with any key fob?

The maker says it blocks the signals of key fobs and other small devices, but the page does not list car brands or fob types. Check by trying the fob in the sealed bag next to your car.