【100% Satisfaction】Our TECKNET wireless doorbells are approved by FCC, CE, and RoHS; ALL TECKNET products offer 36 months warranty (registered only). 【Waterproof & Energy-saving】The doorbell wireless waterproof is made of recyclable ABS materials, with IP65 high waterproof performance to withstand harsh weathers, allowing installation outdoors and no need for waterproof cover (working between -4°F to 140°F). The doorbell button adopts intelligent power management tech, ultra-low power consumption, offering a 3-year lifespan. 【1300ft Long Wireless Range】The wireless door bell receiver has an enhanced antenna to receive long distances signals. Wireless signals with super penetration ability can easily pass through steel doors, wooden doors, walls. 1300ft ultra-width coverage, whether you live in a large or multi-story house, you can timely answer the doorbells. Never miss a visitor! 【60 Ringtones】45mm stereo speaker of doorbell wireless for home delivers CD quality sound; 60 pleasant chimes allow you to set different ringtones for each door. 5 volume adjustment with a max volume of 110 dB, which can cover a 2000ft² house, and the elderly or the hearing impaired can answer the doorbell. 【Expandable & Multifunctional】The high-frequency electronic tech classroom doorbell wireless adopts an FM signal scheme, with strong anti-interference, and multiple sets can work separately. No cross-talking with the next door. Perfect to use in apartments, classrooms, home, offices, hospitals, restaurants, and factories. It's also a night light or pager for the elderly. 【Easy Setup & Use】The electronic doorbell no need for WiFi connection or wires. Just stick the button on the door and plug the receiver into an outlet. Smart memory function preserves your last set melody and volume after a power outage, no need to reset repeatedly. (Not recommended to install the mini doorbell button on a metal door, you can install it on the wall nearby the metal door)