The WR-400 Wireless Relay Kit, from Jackson Systems, wirelessly control hundreds of HVAC applications and provides the perfect solution for broken or missing wires. The easy-to-install, four channel relays use an RF signal to open and close dry contacts. The relays do not rely on Wi-Fi for communication. The Wireless Relay Kit provides a cost effective alternative to running additional wire and can energize a relay up to 100'. A limitless number of WR-400 Wireless Relay Kits can be installed in the same building.