Wireless Door Chime, PHYSEN Door Open Entry Alarm Chime Operating in Range 600 feet,52 chimes,1 Magnetic Door Chime Sensor & 1 Plug-in Receivers For Home Security 52 Music with Loud dB 52 unique ringtones/chimes with 30-110dB volume range allow your wireless door entry alert system to meet any need. Mini Contact SensorThey are small size and can be installed or placed at any in door position.1 year warranty,any quality problem,please contact us directly. Size:big door magnetic(Size:1.77*0.95*0.35inch),small door magnetic(Size:0.9*0.35*0.31inch). Wide Working Range The range of wireless doorbell up to 600 feet in OPEN area, magnetic door sensor will automatically trigger the receiver when separated and the receiver will alert immediately whenever the door or windows is opened. Easy to Install Requires no wiring, Just plug the door entry alarm receiver into any standard outlet, Tear the double sides adhesive tape which on the black of mini door sensor and stick them to the door or window. Lowest Power ConsumptionMini magnetic door chime introduces the latest technology and gives attention to practicability, thus realizes low power consumption and the service life of door sensors up to about 20,000 times.