Evernary dog door bell is easy installation, modern&stylish design The receiver: Simply plug it to an Ac outlet The transmitter: Just mount them where you need They can be placed on the doorfloorwall for easy use with a paw or nose, no damage to the wall In fact, we even can place it to a small board, and let it laying there by the door or where we liked When we are training our dog, can place it where needed You can do your training during feeding time Put the food outside the door, and then show the dog how to ring the bell When they do it, praise them and immediately open the door Put your dog out any time they ring the bell, whether they want to or not Puppy would ring it and when Id come over to let him out, maybe he didnt want to go out, just wanted to play So put them out anyway If youre consistent about it, they will only ring when they want to go out Technical Parameters Receiver working voltage: 110-260V Transmitter Battery: 12V 23A alkaline battery Working temperature: 30Ac +70Ac Transmitter waterproof grade: IP55 Operation range: 800+ feet (open air) VOLUME: 5 Levels (0-110 dB),unique mute-free mode, giving users a better home experience 55 Ringtones: The pairing method is simpleUsers can set any music as doorbell ringtone according to personal preferencePacking List Plug-in Receiverx2 Transmitterx3 hook and loop x3 User manualx1 23A 12V Batteryx3 (included) Mini screwdriverx1