Perko's 1637DP0CHR Vertical Mount White All-Round Pole Light is certified for use on sail or power driven vessels under 20 meters in length. This all-round pole light has a vertical mount and folds down 90 degrees in either direction along the plane of the attachment plate. This light features a polymer top and base and a frosted lens. It also features a 3/4" aluminum tube. One 12 volt bulb is included with the light. The overall height of the light is 14-1/8" and it has a base dimension of 2-1/4" x 5/8". The required screw size for installation is #8.