This sensor detects whether a door is open or closed and communicates with a Z-Wave gateway.Door window contacts should blend in with their environment and these contacts does just that by being one of the smallest in the industry. Each sensor comes in standard white with an optional and included brown cover. This allows you to quickly change the color to best match the decor. It's designed to work as well or better than the original manufacturer models, uses a long life lithium battery and is compatible with major alarm panel manufacturers.