This is an Ethernet Controller board which could be compatible with the 16-channel relay. Using the controller ule and the 16-channel relay, you could control up to 16 devices remotely on LAN or WAN. The Ethernet controller board has integrated the web server, when you are in office, you just need to open the page on your computer, pad or smart phone, and then control your devices like lights, air-conditioning or refrigerator at your home. You can feel free to enjoy the remote controlling of your other devices with the Ethernet controller board.RJ45 interface, via RJ45 telecommunications connection for network control. Unique dual TCP connect control, corresponding with above trait, local as TCP server, accept client control when connect to remote server as TCP client. Relay Size: 18*10*4cm/7.08*3.93*1.57 inch Default IP: 192.168.1.4 prot:30000 https://192.168.1.4/30000 (You could change the default IP address) HTTP Comment: http://192.168.1.4/30000/00 : Relay-01 OFF http://192.168.1.4/30000/01 : Relay-01 ON http://192.168.1.4/30000/02 : Relay-02 OFF http://192.168.1.4/30000/03 : Relay-02 ON http://192.168.1.4/30000/04 : Relay-03 OFF http://192.168.1.4/30000/05 : Relay-03 ON http://192.168.1.4/30000/30 : Relay-16 OFF http://192.168.1.4/30000/31 : Relay-16 ON http://192.168.1.4/30000/41 : Enter http://192.168.1.4/30000/40 : Exit http://192.168.1.4/30000/42 : Next Page http://192.168.1.4/30000/43 : Next Page Color: blue + black Material: PCB Package Includes: 1 x Ethernet Control ule with 16-Channel relayOnly the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.