Made a batch of double layer Faraday pouches, mostly for cell phones so they don't interfere with avalanche transceivers, but could be used for push button start key fobs on a shuttle so you can lock the fob in the vehicle. Or you just use a couple layers of tinfoil? Faraday material was a PITA to work with, very thin and the edges frayed easily.
I am selfishly giving these to my backcountry ski buddies...
View attachment 73132
View attachment 73131
The pouch works, my (5G) phone loses cell, wifi and bluetooth connectivity when inside. Basically a loose copy of:
Maximize avalanche beacon search performance and save critical time by preventing cell phone interference. The Phone Faraday is an essential part of your backcountry safety equipment. It allows you to keep your cell phone immediately at hand for the camera, navigation tools, and communication...
www.tightchutes.com