The SQUARE LIGHT BUTTON D21X by DoorBird is designed for D21x IP Video Door Stations, enhancing user interaction with its white backlit rectangular light push button. It operates within a voltage range of 1-24V AC/DC and supports a current of 1A, ensuring compatibility with various electrical setups. This component integrates seamlessly with DoorBird's video door station systems, offering reliable switching functionality essential for access control interfaces.