Shine a powerful light into the waterTwo bulb options provide underwater illumination with either a 25 (3000CP) or 40(1700CP) beam, with two included halogen bulbs and reflectors. Constructed of polished bronze with plain bronze mounting rings, a Safety Seal design prevents water intrusion if the glass lens breaks. Removing the back of the thru-hull allows easy access for changing bulbs. The 50W light is rated at 800 Lumens of brightness, with a lab-rated bulb life of 5000hrs. Overall length 6" Flange diameter 3-3/4" Body diameter (and cutout size) is 2" Includes 10' of 16/2 electrical cable, and terminal to attach bonding wire Five-year warranty.