Amoker Wireless Doorbell with 1 Mechanical Energy Remote Button and 1 Receiver Operating with Over 36 Chimes, No Batteries Required for Remote , Receivers with LED Indicator Could turn on / off the voice of the bell No Batteries Required for Remote for Mechanical Energy The blue LED flashes when someone is knocking at the door Offers a total of 36 chime tones, from the traditional Ding Dong to various well-known melodies, and 3 levels of adjustable sound volume , meet the needs of different environment Easy installation. Push button can be fixed to the doorframe with the screws provided, or attached to the wall using double-sided adhesive tapes, and door chime can be plugged into an electrical outlet in your home