High Power 7000mw Professional 4-Channel Wireless Audio Video TX Transmitter & Receiver Link. by YanTech USA Brand new Wireless Transmitter & Receiver kits you can set up in 5 minutes; Small compact size and light weight, high sensitivity and low power consumption Up to 3 miles with antenna or 7000 feet without antenna "line of sight" (LOS) outdoor in open area; Locked frequencies/channels to avoid possible interference (see Note in Product Description below) 4 channels optional to transmit simultaneously; Band transmission 1.2GHz (Contact us for 2.4 GHz system) Standard RCA type audio/video input and output! (single audio line); Built in Internal cooling fans You can set up a wireless 4-Camera surveillance monitoring system: with four of this 4-Channel Wireless Transmitter and one Receiver sets, you can connect up to 4 different A/V cameras using 4 different channels and transmit simultaneously without interference! If you want to see all four camera views on the same screen in a split sections, you can add a SMALLEST Portable 4 CH Color QUAD Processor Multiplexer. Contact us to get a QUAD Processor or Micro/Security Cameras at a discount price!