General description This wireless doorbell features the latest RF push and battery-free technology, eliminating the need for wires or batteries, making it environmentally friendly and cost-effective. When the transmitter is pressed, it generates its own electric current and sends a stable signal to the receiver, ensuring reliable performance without the hassle of battery changes. With 38 ringtones and 4 volume levels, including mute, this doorbell allows you to customize your alert to suit your preferences. It also has a memory function that retains your last settings after a power failure, ensuring convenience and ease of use. Technical specifications Transmission power: Automatic power supply Doorbell receiver power supply: AC 110-240 (V), 50/60 Hz Receiver power consumption: 0.25 W Ringtones: 38 melodies Volume level: 4 levels Transmission range: up to 152 m (in open area) Operating frequency: 433 MHz Operating temperature: -4°C to 140°C Installation Installation is