"Product Description Material: Plastic Color: Black Waterproof Level: IP55. Working Temperature: -30C +70C Working Distance: 300m (without barrier) Operating Frequency: 433.92 Volume: 0-110dB (5 adjustable levels, with mute control) Transmitter Battery: 12V 23A Zinc-Manganese Alkaline Battery (Built-in) Receiver (Length x Width x Thickness): 6*6*1.5cm Transmitter (Diameter x Thickness): 7.8*5cm Package Includes: 1 * Receiver, 1 * Transmitter 1.Easy to Trigger The Bells of dog just need to be easily pushed or prodded on the touch pad to activate the wireless doorbell by nose or claw. The distance between two bells is about 20 seconds. No need to press. Any small or big dog can do it. 2. EASY INSTALLATION All dog doorbells for potty training are wireless. Stick the transmitter on the door/floor/wall with 3M double-sided tape, even on a board, then place it where you need. Just connect the receiver to a power outlet. The proper method is simple and easy to use. 3. Adjustable Sound and