Detailed Product Description Cell phone jammer/ mobile phone blockers The products-KYP0030 with ALC power control.it is for install in cars while the motor runing and no effect for other system in cars such as satalite control or security system.. Technical specifications: 1. Effective shielding range: 4-50 meters 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. Power adapter: 12V