This product is a transmitter unit for use on wireless doors or windows, and it comes from the DSC home security brand. The transmitter has the model codes WS4945 and 80008819 and comes in a compact white casing that can be attached to walls or doors in concealed locations. It weighs 0.15lbs, measures 1.8 x 1.6 inches, and uses wireless technology to instruct doors or windows to open or close as required.