JacobsParts Circular Metal 16mm Momentary Push Button Switch (Red) For boat horns, starter switches, and other applications in which temporary activation of an electrical current is desired Operation Type: Momentary (Activates when pressed, deactivate when released) Diameter Required for Mounting: 16mm Faceplate/Button Diameter: 18mm Waterproof Rating: IP67 (may be fully submersed in water without damage)