Features: Wireless Doorbell: No battery needed, this self-powered wireless doorbell allows you to press and generate electricity, eliminating the hassle of wiring and making installation a breeze. Multiple Receivers & Transmitters: Connect up to 5 transmitters to one doorbell receiver, providing convenience for different areas of your home or office. Versatile Applications: Ideal for home care monitoring, alerting you when someone is at the door. It can also be used in hospital rooms for patients to call for assistance, as well as during nursing or pregnancy periods when a quiet call is necessary. Customizable Melodies: With 38 available melodies, you can easily change the ringtone to suit your preference. The high-quality sound ensures clear and pleasant tones in various styles. Long Range & Durable: The wireless doorbell receiver has a signal range of up to 200 meters (656 feet) without obstruction, and 50-70 meters (164-230 feet) with obstacles. The self-powered transmitter is made of flame-retardant PC material, ensuring durability and reliability. Specifications: Doorbell Receiver Power supply: AC100V-230V50/60Hz Power consumption: 0.25W Ringtones: 38 ringtones Signal Distance (without barriers): 200m (656ft) Signal Distance (with spacing): 50-70m (164-230ft) Ringer volume: 80dB/1m (3.3ft) Environment temperature: -10~+45 Product Material: Flame retardant PC Power Supply Plug: EU Plug, UK Plug, US Plug (optional) Size: 8.5 * 5.1 * 2.1cm/3.3 * 2.1 * 0.8inch Item Weight: 150g/5.3oz Doorbell Transmitter Power Supply Method: Self-generating Signal Distance (without barriers): 200m (656ft) Signal Distance (with spacing): 50-70m (164-230ft) RF Frequency: 433MHZ Operating Temperature: -20 ~+60 Size: 4.2 * 2.1 * 8.1cm/1.7 * 0.8 * 3.2inch Item Weight: 65g/2.3oz Note: Due to the different display screen and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Packing List: 1 x Doorbell Receiver 1 x Doorbell Transmitter 1 x Screw Pack 1 x Instructions 1 x Adhesive Tape