Self-Powered DesignNo batteries required for the transmitter, energy-saving and maintenance-free for long-term use.IP44 Waterproof GradeReliable waterproof performance, suitable for outdoor installation and rainy weather.38 Optional RingtonesRich chime selections with adjustable volume to meet different family preferences.Strong Wireless SignalStable long-range transmission ensures no missing rings in home and villa.Easy InstallationSimple paste & plug-in setup, no wiring needed, perfect for home security use. | Cluzine | | Wireless Doorbell Self-Powered Waterproof Smart Doorbell 38 Chimes Home Security Door Bell | Best Buy