RUDDER ANGLE-BLK This is a genuine Mercury Marine factory OEM part, not aftermarket.Fits in 2-1/8" (52mm) hole.Round, black gauge face indicates the angle of your rudder or engine to the transom of your boat fits in 2-1/8 in. (52mm) holeGlass lens for durability and long service lifeWorks with all SmartCraft compatible enginesBezels are sold separately from each instrument allowing for the boater to select the color of their choice to complement or contrast with the face of the instrument