So you would like to detect smartphones used in sensitive rooms? This Wide Area Cellphone Detector has you covered. It comes with five cellphone frequency antennas. It offers adjustable sensitivity for each band. The audible alarm comes with customizable message.
The device can detect any cell phone call, text or data usage in a 20 meter radius. It can detect LATE 700, GSM 850, 3G/CDMA 850, GSM 1900, and CDMA 1900 frequencies.