Feature:1. Reliable Material: This product is made of ABS material, which is sturdy, durable, and not easily damaged, and has strong waterproof performance; If installed outdoors, it will not be damaged even if it is exposed to rain.2. Music Function: The door ring has 36 ringtone music and 4 adjustable volume levels to choose from; Multiple ringtones can be selected according to user preferences; The volume can be adjusted to meet different space requirements.3. Product Performance: This product is lightweight and sensitive, with LED flashing warning on the receiver; The operating range in an open area can reach 1000 feet, with strong penetration, ensuring that you hear the bell and open the door in a timely manner.4. Convenient Installation: The door ring receiver is plug in mounted, and the transmitter is powered by a 23A 12V battery (not included); Install the transmitter at the outdoor door, and users can hear the doorbell indoors with a gentle press.5. Applicable to: This product is suitable for various places, such as shops, families, bedrooms, warehouses, villas, etc., facilitating the daily life of users.Specification:Item Type: Intelligent door ringWeight: 300g/10.58ozReceiver Size: 28x76x80mm / 1.1x3.0x3.1inTransmitter Size: 20x48x78mm / 0.8x1.9x3.1inTransmitter Power Supply Battery: 1x 23A 12V battery (not included)Function: 36 music with 4 volume levels.Package List:2 x Receivers1 x Transmitter1 x Instruction1 x Screwdriver1 x Adhesive2 x Expansion Pipes2 x ScrewsNote:Transmitter shipped without battery.