... around your homeDoor chime trigger by motionDon't miss a visitor / customer / friend / clientSuitable for Home, Office, Unit, shop, ... chime is triggered by detecting the motion of the visitor passed by.1 inch diameter, 0.25 W speaker ... DOOR BELL CHIME MOTION SENSOR WIRELESS ALARM1 set x 180 degree wall mounting bracket Wireless home alarm system,Light control distance 3-7 meters,entry door bell ...