Review on Mengshen Blocking Anti Hacking Protector Wireless by David Pirlet

Holds a new keyless fob for my son's new car fairly well. It's plastic, but it blocks the transmitter signal perfectly. Easy to put/remove from pocket. NOT for a full set of keys - and not for a cell phone - make sure you look at the dimensions and add the thickness of your phone if that's the use you have in mind. Good for traveling, especially. If your room is too close to your car without blocking the signal, your car may be left unlocked. This must be supplied with the key ring for all new vehicles with such devices!