The PFM810 set allows to send power supply and video signal from CCTV camera via single coaxial cable for maximal distance of 400m. The device is designed to work with 75Ω impedance coaxial cables.
So, the coaxial cable passing the voltage to the camera and video signal from camera to the recorder. The maximum distance is determined by the quality of coaxial cable used.
Attention! The device operates as a dedicated set. The transmission line between the transformer A and transformer B can not contain any additional devices (video splitters, amplifiers, etc.). You should use only the coaxial cables with copper core. For indoor use only. Protect from moisture and dust.