Smart Battery Electronic Unlimited Self-English Simple Wireless Regulation Doorbell Self Powered,No Battery Required Button does not need to install battery When pressed, kinetic energy is converted into electrical energy Energy saving and environmental protection, more convenient Really Waterproof IP44 Waterproof Grade Don't worry about extended use in heavy rain Stronger Signal ,Further Distance Signal is stronger, enhanced wall penetration and propagation distance Better chips Advanced Technology Advanced A12 signal processor, super-sensing antenna The digital signal circuit is more resistant to interference. Free Matching Learning Code Technology,Buttons and receivers can be paired freely No Fever,Safer Upgraded IC circuit It will not heat up when plugged in for a long time. Better security.Designed to last up to 26 years Easy Installation No wiring required, no tools required you don't necessarily have to make holes or damage anything. 1.Plug the receiver into the socket 2.Stick the button to the outside wall Reminders? The button cannot be placed on an iron door because it will interfere with the signal. Instructions Parameters Receiving distance: 150M (in open area) Waterproof: IP44 Ringtones: 51 pcs Volume: 4-steps(Can mute) Button power supply : Self powered Receiver power supply : AC 110V - 250V Plug Type: BK / EU / US / AU Working frequency: 433 MHz