SURFACE MOUNT: this doorbell push button can be easily installed on almost any wall or flat surface area SPECS: total length: 2.74"; distance between screw holes: 2.06" MAXIMUM VOLTAGE: when installing and using this push button doorbell, do not exceed 16 volts SATIN NICKEL FINISH: a modern and timeless nickel finish pairs well with any contemporary, traditional, modern, industrial, Scandinavian, or minimalist exterior décor you may already have WARRANTY: this push button doorbell is guaranteed with a 1-year limited manufacturer's warranty