Features: Connect to DC 12V power directly. Can be used for a long time The door bell is not include switch. A good replacement for the old and broken one External wired door bell for security access control The door bell has featured with soft, loud and clear ding dong playing bell sound Switch is not included. A good replacement for the old and broken one Specifications: Condition: 100% Brand new and high quality Color: As picture shown Voltage: 12V DC Operating Current: 20mA Environment Temperature: -10℃-45℃ Relative Humidity: 40%RH-90%RH Installation: Wall-mounted or double-sided adhesive(not included) Size: Approx. 8.6 * 8.6 * 2.5cm / 3.39 * 3.39 * 0.98in Weight: Approx. 90g Wire Connection: Red: + 12 V Black: GND Green: BELL1 Yellow: BELL2 Package Included:  1 * Door Bell Features Connect to DC 12V power directly. Can be used for a long time The door bell is not include switch. A good replacement for the old and broken one External wired door bell for security access control The door bell has featured with soft, loud and clear ding dong playing bell sound Switch is not included. A good replacement for the old and broken one