And with that: Cellular devices are designed to transmit some kind of pilot signal even when turned off but with operational battery http://www.endoacustica.co

And with that: Cellular devices are designed to transmit some kind of pilot signal even when turned off but with operational battery http://www.endoacustica.com/gsm_interceptor_en.htm http://www.endoacustica.com/gsm_interceptor_en.htm