Hydro-Stabilizer for Outboards & Stern Drives – 50 horsepower & Above. The Hydro-Stabilizer quickly puts your boat on a plane and helps pull skiers out of the hole faster. The wings also provide a smoother, more stable ride for you and your passengers; designed specifically for 50 HP outboard and stern drive engines.Features: Wings constructed of durable, molded black plastic. Includes all needed bolts and lock nuts for installation, in premium stainless steel. Out-performs ordinary flat hydrofoils by reducing drag when the hull goes on a plane. Effective even at lower RPMs for outboards and stern drives of 50 horsepower and above.