Wireless Door Sensor Chime, ELEPOWSTAR Door Open Chime Window Alarm for Office/Home/Store, Operate Range 600 feet with 52 Chimes and 4 Volume Levels, Black (1 Door Sensor+1 Plugin Receiver). Easy to install and easy to use. Great for security purposes on a business entry door. Nice and loud for ease of hearing from a distance. #Viralix #ELEPOWSTAR #Hubery