Brothers billet aluminum bed hole caps with lights is a perfect addition to any custom truck. They will not only look great but also add safety by becoming additional brake lights and/or turn signals. They are not intended to replace your dot legal taillight/brake light system. Each lamp is 12 volt and uses a common 194 bulb. 1-19/32-inch diameter. These lights fit into the upper edge of the bedside in the tubular opening. Sold as a pair with one light for each side of the truck.