Material: ABS plastic. Environmental, waterproof, flame retardant. Type: wired doorbell. Red: +12V, Black: GND, Green: BELL1, Yellow: BELL2. Working voltage and current: DC 12V/20mA. Ringtones: 3 chords for choice . With the Dingdong ring. With 90dB speaker. Application: suitable for access control system, such as home, hotel, office, apartment, factory, etc. 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 the choice to play bell sound. 3, connect to DC 12V 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 Specification Ringtones: 3 chords Voltage: 12V DC Operating current: 20mA Ambient temperature: -10C-45C Relative humidity: 40%RH-90%RH Installation: Wall mounted Size: approx. 85*85*25mm Material: ABS plastic Weight: approx. 0.1kg 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 high volume speaker, crisp doorbell, not afraid of the owner can't hear. 4, must be powered by DC12V access control power supply. No need to install battery for this doorbell. Wires connection Red: +12V, Black: GND, Green: BELL1, Yellow : BELL2 Package List 1 x Doorbell