attwood 9400-7 Marine Boat Hydro-Stabilizer Kit for Outboards and Stern Drive Engines 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 plane Effective even at lower rpms for outboards and stern drives of 50 horsepower and above Attwood products are both Compatible and reliable, engineered and built with a never-fail attitude Gives outboards and stern drives a performance boost, improving both stability and handling Hydro-stabilizer for outboards and stern drives 50 HP and above Installs on a large variety of motor styles and sizes with included stainless steel bolts and lock nuts Wings constructed of black molded plastic and hydro-stabilizer outperforms ordinary flat hydrofoils by reducing drag when the hull goes on plane The hydro-stabilizer quickly puts the boat on plane, and helps pull skiers out of the hole faster, even at lower RPMs, it keeps the boat on plane The wings provide a smoother, more stable ride and reduce ventilation in turns