Review: Monojoy keyless car key signal blocker
reviewed 28 Jan 2019 by Georgia Petrie





The pouch works as a Faraday bag to prevent keyless car theft

Small enough to fit in pockets or handbags

Pouch isn't big enough for multiple keys

What is it?

Keyless entry car theft is a very real issue, with expensive models in built-up areas particularly at risk. The number one way to prevent keyless entry theft is to stop the key from being vulnerable by blocking the signal. Thieves use relay devices (which you can easily buy online) to amplify the signal from the key fob in your home to a transmitter near your car, which essentially tricks your car into thinking the key is present.

This allows them entry into the car, where they can use the start-stop button to start the car without the key. The key also doesn't need to be present within the car for it to continue running - so they can keep driving as long as the ignition isn't turned off at any point.

If you don't want to put your faith in physical solutions like the Disklok steering lock, then Faraday bags are a good preventative measure. They work by blocking electromagnetic fields, which stops radio frequencies from being amplified - meaning your car can't be stolen without the physical key.

What's it like?

The 20cm x 10cm Monojoy pouch is a great, cheap bit of kit for anyone who's worried about waking up to find their car stolen. And with this purchase, you get two pouches.

It's pretty small, meaning our Audi key fob fits inside, and you could get a house key or another key fob in there as long as they aren't massive. The RFID blocking material also means you can put building access keys, smart watches etc in there to protect them too - although we haven't tested the product for this purpose.

One example of a keyless car theft that took less than 2 minutes

Considering the rise in keyless entry theft, the size of the bag is also good because it means you can put it in a pocket or bag and carry it around with you. This prevents thieves who wait for you to park and leave your car before blocking the signal, meaning they can get into your car using a signal extender even after you've walked a few hundred metres from the vehicle. With keys inside the pouch, it can be a bit bulky for a pocket though.

The signal is completely blocked inside the pouch, so even if you put it in your pocket and the buttons get accidentally clicked, your car won't unlock. The only downside is that the velcro can be a bit annoying, something a bit less basic might have been a nice touch considering the velcro pulled the wool off one of our jumpers...

Should I buy one?

Yes, if you're worried about your car being stolen then it's a great investment. For £8, which is the retail price at the time of writing, you get peace of mind about leaving your keyless entry car outside your house. Even if you don't have keyless start, those who can gain entry can steal anything you leave inside your car.

And, if they're old-school, they could hotwire it and drive it away...

Buy it now

Faraday Pouch for Car Keys - Car Key Signal Blocker Pouch | Keyless Car Key Signal Blocker Pouch, Faraday Pouch For Car Keys 2 Pack, RFID Key Pouch Defender Signal Blocker Key Pouches Signal Blocker

Pros Small enough to fit in bag or pocket Works consistently Much, much (much) cheaper than steering locks and OBD anti-theft systems
Cons Pouch is too small for multiple keys Velcro can be irritating


20cm x 10cm

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