This Everspring EVR_SP814 Z-wave motionsensor with PIR (Passieve Infrarood Reciever) detects motion in an aera. This Z-wave sensor sends the information to a Z-wave controller. The maximum Z-wave devices that can be connected via association is 4. The unit sleeps until motion is detected, but wakes up after a set interval to recieve and sent commands from and to the z-wave controller. Its battery operated and will sent a message when the battery is nearly empty.