This product is designed to extend battery operating time and reduce power consumption, helping keep your video doorbell running efficiently. Before using this product, remove the battery from the doorbell. Easy to installsimply route the cable through the door opening and connect it to your doorbell. Installation and setup can be completed in minutes. No existing doorbell or additional wiring is required, and it can be installed on most doors. The cable length is 5 meters. Compatible with Nest Hello, Arlo Video Doorbell, Eufy Video Doorbell, Simplisafe Video Doorbell, Zmodo Smart Greet Wi-Fi Video Doorbell, and other doorbells that require an 18V adapter. Constructed with high-performance materials for durability. The design is smooth and flexible, with a flame-retardant, impact-resistant PC-ABC outer casing that is safe for human contact. The power supply features an anti-slip matte finish. Resistant to gloss, oxidation, and humidity. Built to strict manufacturing standards with fully insulated layered winding for enhanced safety and longevity.