The Cell Phone/GPS Detector is able to detect all mobile phone activities including: SMS and MMS messaging, audio phone calling and data transmitting. This detector is ideal for radio frequency (RF) engineers and technicians. Offers wireless signal detection in theaters, restaurants, trains, buses, library, governement facilities, financial institutions and testing centers. It has adjustable sensitivity and frequency band and buzzer or vibration alert. Detector shows an instant display of scanned frequencies. Note: This item only detects cell phone/GPS signals when transmitting.