Product Features 1, Wired external door bell for security access control. Can work with access control keypad, power supply, electric lock and other access control products. 2, Featured with soft, loud and clear 3 ringtones for choice to play bell sound. 3, Connect to 12V DC power supply directly. Can be used for a long time. 4, Easy to install, wall mounted. 5, Switch is not included. A good replacement for the old and broken one. Product Details 1, Using ABS flame retardant material production, fire prevention, high temperature resistance. Can be used for a very long time. 2, After the product is connected to the access control system, press the access control doorbell button to create a pleasant ringtone. 3, 90dB loud speaker, crisp doorbell, not afraid the owner can not hear. 4, Need to be powered by DC12V access control power supply. No need to install battery for this doorbell. Product Specifications Ringtones: 3 chords Voltage: 12V DC Working Current: 20mA Ambient Temperature: -10°C-45°C Relative Humidity: 40%RH-90%RH Installation: Wall-mounted Size: Approx. 85 * 85 * 25mm Material: ABS plastic Weight: approx. 0.1 kg Wire connection Red: +12V, Black: GND, Green: BELL1, Yellow: BELL2 Package List 1 x Doorbell