Wide CompatiblityExtra Long 19.7ft Cord 18v universal US power cable powers popular smart doorbells. Compatible with Ring Video Doorbell, Ring Video Doorbell 2 & Ring Video Doorbell Pro, Skybell, Nest, Eufy, Arlo Doorbells, etc. Continuously converts 110/120v to 18volt 500ma. High-Quality MaterialThe outer shell of this product is made of fire-proof injection molded shell, and the interior is made of pure copper wire core. Based on electromagnetic induction, the stable AC current output allows your doorbell device to work for a long time. NOTE Before purchasing, please confirm that the voltage and current required by the doorbell or thermostat match the power supply. Please connect the doorbell before connecting the power supply, and be careful not to let the two cables connected together cause short circuit. Easy to install Connect the two ring terminals to the screws at the back of the doorbell. The wire ring design makes it easier to install and helps ensure the a