Zero Interference with Bluetooth, Wireless Routers, microwave ovens etc 100% safe signal, privacy guaranteed Alarm-alert when signal dropout Distance up to 200m in the open area Compatible with up to 4 cameras Waterproof night vision camera with excellent audio AV output System Specification: Camera: Model No.: CM713 Image Sensor: 1/4" CMOS Video Quality: 380 TV lines Effective Pixels: PAL: 628 x 582 NTSC: 510 x 492 Minimum Illumination: 3Lux./F1.2 Microphone: YES Audio Range: 3 Meters( 9ft.) Operation Power: DC5V Operation Tempe ration: -20~60°C Analogue or Digital: Digital Maximum Transmission Range: 200m in the open area Frequency: 2.4GHz Digital (Frequency Hopping) Camera Supported: 4 Cameras Maximally Receiver: TV System: NTSC/PAL Video Output: 480(W)*240(H) Receiving Signal: Video & Audio