With EU/US/UK plug optional, this wireless doorbell is suitable for most countries. Using digital circuit design, this wireless doorbell has no string noise. And it is loud enough to be heard anywhere in the home. It is constructed of ABS material. The length of the transmitter is 7.5cm, the width is 5.1cm and the height is 2cm. The length of the receiver is 9.5cm, the width is 6.5cm and the height is 2.4cm. Stable quality is ideal for villas, hotels, schools and other areas. You can set different music for different buttons Item Name: Wireless Doorbell Material: ABS Model: A10 Socket Type: EU Plug, US Plug, UK Plug (Optional) Battery: 12V 23A Battery (Not Included) Voltage: AC 110V-220V-240V Frequency: 433MHz Volume: 0~110dB Receiving Distance: 300m Features: 60 Chime, 5 Volume Levels, Long Receiving Distance Size Details: Transmitter Size: 7.5cm x 5.1cm x 2cm/2.95" x 2.01" x 0.79" (Approx.) Receiver Size: 9.5cm x 6.5cm x 2.4cm/3.74" x 2.56" x 0.94" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. The wireless signal will be affected by obstacles. The more obstacles, the more serious the signal loss. The button cannot be placed on an iron door because it will interfere with the signal. Pairing Method: Hold down the volume key on the receiver for 5 seconds, immediately press the button, the signal pairing is successful. How to Set Music 1. First Press and Hold the Music Button to Select the Music You Like, 2. Then Press and Hold the Volume Button on the Receiver for 3 Seconds, 3. Then Press the Button Immediately, the Music Selection is Successful. Package Includes: 1 x Doorbell Transmitter 2 x Doorbell Receiver (Screws, Double-sided Tape Accessories and Stickers Included)