Product description Material: plastic Color: black Waterproof rating: IP55. Working temperature: -30C to 70C Working distance: 300 m (without obstacles) Operating frequency: 433.92 Volume: 0-110 dB (5 levels adjustable with silent mode) Transmitter battery: 12 V 23 A alkaline zinc-manganese battery (built-in) Receiver (length x width x thickness): 6*6*1.5cm Transmitter (diameter x thickness): 7.8*5cm Package 1 contains: 1*receiver 1*transmitter Package 2 contains: 1*receiver 2*transmitters 1. Easy to activate The dog bells only need to be simply pressed or pushed over the touch pad to activate the wireless doorbell with the nose or paw. The distance between two bells is approx. 20 seconds. No need to press. Any small or large dog can do it. 2. EASY INSTALLATION All dog doorbells for potty training are wireless. Attach the transmitter to the door/floor/wall with 3M double-sided tape, even on a board, and then place it wherever you need it. Simply plug the receiver into a power outlet. The method is simple and easy to use. 3. Adjustable sound and volume The smart dog doorbell offers 55 ringtones and 5 volume levels from 0dB to 110dB to choose from. Set it to 0 dB (silent) when you need it. 4. 300 m wireless range The pet doorbell comes with transmitters and receivers. Transmitters and receivers can be easily paired. Stable signal transmission and good interference performance. 5. IP55 waterproof The built-in waterproof sealing ring can protect the elements inside from water and dust to extend the service life. It can work normally on rainy days.