Mercury Outboard Bar Zinc Anode Located on the bottom of the external power trim pump assembly. Length: 7-1/2" Width: 2" Thickness: 1/2" Hole Diameter: 1/4" Weight: 1.5 lbs Fits: Mercury/Mariner 30/40 FourStroke 40 (4 cylinder) 50 (3 cylinder 1987-1997) 55 (3 cylinder) 60-90 (3 cylinder 1987 & newer) 75 (4 cylinder) 75/90 FourStroke 100-125 (4 cylinder) 115 (6 cylinder 1984-1988) All V-6 and OptiMax outboard engine