【Latest RF Push Technology, No Batteries Required】 This wireless doorbell is self-powered, requiring no wires or batteries, making it environmentally friendly and cost-effective. When you press the transmitter, it generates electricity and sends a stable signal to the receiver. No need to worry about damaging your wall or doorbell when replacing batteries! 【38 Ringtones & 4 Volume Levels】 Our wireless stereo doorbell speaker delivers full, clear sound quality. It offers 38 ringtones and 4 volume levels (including mute) to suit your personal preferences. Press and hold the volume button to return to the first ringtone (ding-dong). The wireless doorbell has a memory function that remembers your last setting, even after a power outage. 【No Crosstalk or False Alarms】 This compact wireless doorbell boasts strong penetration and anti-interference capabilities. The range can reach up to 152 meters (500 feet) under various obstacles and up to 305 meters (1,000 feet) in open spaces. It won't affect other devices in your home or your neighbors' homes, so you won't miss any visitors, even if you're several rooms away or on different floors. 【Easy Installation】 Simply plug the mini receiver into a wall outlet and mount the transmitter on the wall with the included accessories (including two screws and a piece of adhesive tape). Our doorbell is suitable for use in homes, apartments, schools, villas, offices, and more. This battery-free, wireless doorbell also makes a great holiday, birthday, or anniversary gift for any homeowner or business owner. Specifications: Transmitter power: self-contained; Doorbell receiver power supply: AC 110V-230V, 50/60Hz; Receiver power consumption: 0; Ringtones: 38; Volume: 4 levels; Transmitter range: up to 152 meters (open space); Operating frequency: 433 MHz; Operating temperature: -4°C to 140°C