Kit Includes: Safe-Skeg, Mounting Hardware, Instructions, Allen Wrench and Loctite 262 Brilliantly Polished with a Seamless Design Contains a Drain Hole to Protect Against Corrosion and Freeze-Up For: Mercury/Mariner Outboard – 135-150-175-200 HP Optimax, 2 and 4 Stroke from Years 1978 through 2011 AND 225 HP, 2-Stroke from Years 1978 through 1995 Material Thickness: 1.5mm (50% Thicker than the Competition) All Sierra parts qualify for and are covered under Sierra's Industry Leading Customer Satisfaction Warranty