Use twisted cable instead of coaxial cable to transmit video, audio signal in effective distance 450-600M, adopt Differential transmit theory, better performance at anti-common code interference, even at strong interference application, its performance is much better than coaxial cable, and through processing video signal, its image clearer, each twisted cable at most can transmit 4ch audio or video signal, it is at most save cost.3 rate Lightening-protection, fire-resistant,, heat-resistant, anti-static, low EMI, circuit transient impact protection. Small size, can be installed inside the protective cover of the camera. simple installation, no debugging. size : 32*21*15 weight: 18g