For very important places such as prisons, it is very important for the military and certain special government agencies to protect information from disclosure. In this case, it is indeed necessary to block the signal of the mobile phone. If in this case you need to use it to cut off the 3G mobile signal, then this Prison Signal Jammer is indeed a good assistant.
Cell phone and WiFi Signal Jammer from jammerinthebox got good quality and suitable price. Anyone in need? Please contact us.