Main features: o According to the current mobile system frequency of CDMA, GSM, DCS and PHS used at in abroad, we adopt high-tech to provide shield for mobile signal from them in special area that can not communicate with the station, so as to get to the active shield for use mobile phone o Use mobile phone signal jammer at the places more than 200m away from the base station for best performance o When switch on, it can work steady for a long time • Applications: 1. Museums, Libraries, Lecture rooms, Prevent students from sms cheating, Theatres, Schools universities, Restaurants, Places of worship, Country clubs, Sporting events, Recording studios, Tv stations, radio stations