Sierra International 35-SS605 Marine-Grade Stainless Steel Panther Safe-Skeg for Mercruiser I/O Alpha 1 Drives, 1985 to 1990 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: Mercruiser Inboard/Outboard  Alpha 1 Drives, Years 1985 through 1990 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 Before Ordering, Please Verify this is the Correct Part for your Application. For Assistance, Please Call Sierra's Tech Support at 1-877-663-8396