Detailed Product Description Cell phone jammer/ mobile phone blockers Technical specifications: 1. Effective shielding range: 10-30meters radius 2. Isolation bandwidth: CDMA: 869-894MHz GSM: 925-960 MHZ DCS:1805-1880MHZ WCDMA:2110-2170MHZ PHS:1900-1925MHZ PCS:1930-1990MHZ 3. Operation temperature: -40c to +55c 4. Humidity: 30% to 95% 5. work time: 3-4 hours work steady for a long time