Features: 1.Self Generating Doorbell: When you press your finger, the kinetic energy is converted into electric energy, free of wiring, no battery. 2.Adjustable Ringtones: 38 ringtones, includes classic doorbell tones and music tones, and 4 level adjustable volumeto meet your personalized needs. 3.Long Range: The wireless doorbell signal has strong penetration, can penetrate 3?4 walls, and the longest transmission distance in open areas can reach 200 meters. 4.Weatherproof: The wireless doorbell is made of ABS material, which is resistant to high and low temperature, waterproof, and effectively prolongs the service life. 5.Wide Application: Doorbells are widely used, can be used in homes, villas, hotels, factories, as well as the elderly, patients, pregnant women, etc., one click call to protect the safety of family members. Specification: Item Type: Wireless Doorbell Set_x000D_ Material: ABS_x000D_ _x000D_ Doorbell_x000D_ Power Source: Self generated_x000D_ Transmission Distance: Open Space: Approx. 200m/656.17ft; Indoor: Approx. 50m/164.04ft_x000D_ RF Frequency: 433MHz_x000D_ Receiver_x000D_ Power Supply: AC110-240V_x000D_ Ringtones: 38 (4 level adjustable)_x000D_ Ringtone Volume: 50dB/1m_x000D_ Uses: Can be used in homes, villas, hotels, factories, the elderly, patients, pregnant women, one key calling. PackageList: 1 x Doorbell 2 x Receiver 1 x Sticker Note: Please supply power according to the voltage used, using other voltages may cause fire and product damage!