Jammer, Cell Phone Jammer, Prison Jammer manufacturer / supplier in China, offering 210W High Power 8 Bands Indoor Signal Jammer with Sheilding Range up to 150 Meters, High Power Jammer 30W 3 Antennas Portable Signal Jammer Blocks 315MHz, 433/434MHz, 868MHz RF Signal Jammer, Coverage Range up to 200 Meters., Cell Phone Blocker Signal Jammer with 12antennas Used in Car Truck and Vehicles and so on.