Resideo V-Plex Contact Overhead Door Sensor Rugged Aluminum Housing 4959SN

V-Plex is the patented polling loop technology that literally defines price and performance on a simple pair of wires. By using two wires instead of four, V-Plex offers significant advantages over home run wiring or the conventional four-wire multiplex-providing economical expansion of peripheral devices and point identification to your central monitoring station.