Die-cast Zamak base with locking knob that allows pole to be lowered to the gunwale when not in use. 2-mile, 360° visibility, for boats up to 39.4' in length. Includes frosted lens and 8 watt wedge-base lamp. Has three countersunk holes for #10 fasteners. Note: adequate clearance is required below deck for pole when lowered. Installation hole size: 7/8" diameter. Base dimensions: 1"W x 4-1/2"D.