Intelligence Wireless Doorbell Waterproof 300M LED Smart House Cordless Bell Battery Doorbell 23A12V Home Electronics|Doorbells(gold) Features and specifications: 1.Press the button, super learning code can freely learn to match, can be unlimited matching receiver. 2.The transmitter without screw chuck design to achieve waterproof and dustproof. 3.The doorbell button usea 23A12V battery (not included) and the receiver voltage is 220v. 4.The receiver is a distance of 300 meters (in an open area), which may be affected by the environment and obstacles. 5.The receiver has 36ringtones to choose from, and the volume is 20-80db in 4 levels. 6.The receiver is available in a variety of plugs, US/EU/UK Plug and AU adapters, suitable for most countries. 7.Transmitter size:86*86*33mm 8.Receiver size:90*62*20mm 9.Just plug the receiver into an electrical outlet,the push button transmitter can be stick it to the door with provided adhesive tapes. 10.The doorbell can use in the office, home, hospital, factory, restaurant or anywhere need it. Note: The button cannot be placed on an iron door because it will interfere with the signal. If the receiver does not ring when you press the button after you receive the doorbell, check the following steps: 1. If the button has a battery installed, it requires an alkaline battery of 23A12V. 2. You can pair the button with the receiver.