Strong anti-interferenceLow power consumptionIdea for home, office, factories, guest rooms in hotel etc..InstallationOpen the battery compartment cover of the receiver and load 4 x R14/C batteries (Not included)Fix the transmitter on the wall near the door with screws or adhesive tapes.Avoid placing transmitter near high temperature moist area, metal or electromagnetic surfacesPlease replace the battery if the transmitter is not functioning properlyPackage Dimensions10.5x5x17cm