The Videotel small red button with text has a black front bezel that is 1 1/4" diameter wide x 3/8" tall. The text reads "D". This button mounts in any 1" hole and is secured with an included plastic nut. The button can be mounted in any material between 1/8" and 3/4" thick. Includes button, fastening nut, 12VDC cluster LED light bulb, light holder, and N.O. (normally open) / N.C. (normally closed) switch.