Use the SH-056SR Wireless Signal Detector to detect different RF wireless frequency signals. It can detect the micro wave of 50MHz wireless camera up to 20 feets, much superior than other high priced detectors which can detect devices at a few inches distance. It can prevent one from being tapped or peeped effectively. Main applications: Holding safety meeting, checking the existence of pin-hole video camera in hotel/toilet/changing room, checking for military organ and governmental bodies, checking for hearing bug/cellular phone.    Products Specifications Detecting Frequency Range 50MHz-2.6GHz Working range 0-20 Feets Battery Life 30 hours Dimensions 79*53*16mm Packages included: SH-056SR Wireless Spy Bug User manual