Features: 1.Self Generating Doorbell: Press the doorbell with your finger, and the kinetic energy is converted into electrical energy, do not need battery. 2.Long Range Control: The doorbell adopts 433MHz wireless signal, which has super penetrating power, and the receiving distance in open areas can reach 150m / 164yd. 3.38 Melodies 3 Volumes: 38 ringtones can be freely switched, 3 volume control, can be set to mute, and the volume of the sound can be determined at will. 4.Wireless Caregiver Pager: This is not only a wasterproof doorbell, but also a caregiver pager, suitable for the elderly, patients, pregnant women. 5.Waterproof: The waterproof level of the transmitter reaches IP44, which can be installed outdoors and indoors, without fear of wind and rain, safe and durable. 6.Installation Method: Come with a strong double sided tape, no wiring required and no damage to the wall, you can also use screws to install the doorbell. Specification: Item Type: Battery Free Wireless Doorbell_x005F_x000D_ Material: ABS_x005F_x000D_ Working Voltage: AC 100V-230V 50/60Hz_x005F_x000D_ Operating Frequency: 433.92MHz_x005F_x000D_ Standby Power Consumption: 0.25W_x005F_x000D_ Ringtones: 38_x005F_x000D_ Volume: 3 Levels + Mute_x005F_x000D_ Controllable Volume: 50dB/1m_x005F_x000D_ Receiving Distance: 150m / 164yd (In Open Space)_x005F_x000D_ Receiver Working Temperature: -10-+45_x005F_x000D_ Transmitter Operating Temperature: -20-+60_x005F_x000D_ Receiver Size: Approx. 78x54x20mm / 3.1x2.1x0.8in_x005F_x000D_ Transmitter Size: Approx. 66x40x20mm / 2.6x1.6x0.8in_x005F_x000D_ Battery Free: The transmitter does not need a battery, it is self generated by pressing PackageList: 1 x Doorbell 1 x Receiver 1 x Sticker Note: 1. The remote control distance is affected by the use environment, and the distance will vary due to different use environments_x005F_x000D_ 2. When using wireless electronic products, you should avoid large electronic equipment, electromagnetic fields and other strong sources of interference, so as to avoid the remote control and the receiving distance being short or unable to work normally._x005F_x000D_ 3. Do not use this electronic product abnormally. Abnormal use will reduce the performance and life of the product. In severe cases, it will damage the product and bring potential dangers to your safety.