“The OFF Pocket™ uses the principle of a faraday cage to block all radio signals from entering and exiting the case. Your phone contains an antennae that communicates with cell towers and GPS systems. Both of these signals, radio waves in the 2.4GHz spectrum, are blocked by the metallized fabric in the case.”The OFF Pocket has been extensively tested on all major networks, including Verizon, AT&T, T-Mobile, and Sprint. It is compatible with all mobile phone hardware including but not limited to iPhones, Android, Blackberrys, Nokia as well as all modern phone operating systems
via Off pocket