High Compatibility - This 24V transformer is perfect for a variety of devices for Nest, for , and for smart thermostats, as well as Ring, Nest Skybell, and other video doorbells. It ensures your devices always have the power they need for optimal performance. Certified Safety & Performance - With an input of 120V 50/60HZ and an output of 24V 40VA, it provides reliable and continuous power, making it a safe choice for your home's wired systems. Power Multiple Devices - Ideal for upgrading underpowered , our 24V AC Transformer can handle multiple thermostats or doorbells simultaneously. It's the perfect replacement for old , ensuring all your devices function correctly without interruption. Designed for quick replacement and setup, it can be securely mounted in any suitable electrical box within your home. Please note:the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:Black & Silver Material:Metal+Plastic Package