CoRui Wireless Doorbell 1 Pull 1 Self Generating Household Remote Control Electronic Doorbell Free Of Wiring Free Of Stickers Working voltage: AC100V-230V 50/60Hz Operating frequency: 433.92MHz Standby power consumption: 0.25W Music: 38 songs Volume: 3rd gear+mute Controllable volume: 50dB/1m Receiving distance: 150m (no obstacle in the open area) Receiver operating temperature: - 10 C -+45 C Working temperature of transmitter: - 20 C~+60 Receiver size: 78 * 54 * 45mm Emitter size: 66 40 * 20mm The transmitter does not need a battery. Press it to generate power automatically Specifications: 1. Self generating wireless doorbell without battery and wiring 2. Press your finger to generate electricity, without battery for life When you press your finger, the kinetic energy will be converted into electric energy, and the wireless signal will be transmitted instantly, so you don't have to worry about changing the battery for the doorbell. 3. Strong penetration and long distance The 433.92 frequency wireless signal is adopted, which can penetrate 3-4 gates with super penetration, and the reception distance in open areas can reach 150 meters 4. Free code matching and rejection of serial ringing Even if a neighbor buys the same doorbell, it will not ring in series. Learning code technology is used. You don't need to worry about stringing lines with the next door. You can also match them according to your own needs to meet home use 5. High volume without leakage, and the third gear is optional