Feature: 1. Adjustable Ringtones and Volume: 58 ringtones to choose from, the ringtone volume is greater than 90dB, and the volume is adjustable in 4 levels to meet your personalized needs. 2. Self Generating Doorbell: When you press your finger, the kinetic energy is converted into electric energy, free of wiring, no battery, and long distance. 3. Waterproof: IP44 high temperature resistance and waterproof, the working temperature range is ‑10°C‑+45°C, effectively prolonging the service life. 4. Multipurpose: Not only a doorbell, but also used as a pager, the receiver receives signals, sound and light reminders, suitable for babies, the elderly, pregnant women, guarding family members. 5. Wide Application: The wireless doorbell has a stable signal and is widely used in various places, such as shops, hotels, office areas, villas, shops, family homes and other places. Specification: Item Type: Wireless Doorbell Set Material: ABS Transmitter Power Source: Self generated Size: Approx. 63x63x20mm/2.48x2.48x0.79inAmbient Temperature: -20°C-+60°C Transmission Distance: Open space > 150M RF Frequency: 433MHz Receiver Power Supply: AC110-240V 50/60Hz Power Consumption: 0.25W Ringtones: 58 Ringtone Volume: ≥90dB Ambient Temperature: -10℃-+45℃. Package List: 2 x Doorbell2 x Internal Machine2 x Sticker1 x Manual