The world's first No-Drill hydrofoil with an optional drill installation feature. This allows boaters to choose which installation method they prefer - No-Drill or Drill. The hidden, no-drill attachment results in no harm to the engine and the quickest and simplest installation process which requires only 2 set screws! Delta-Wing profile adds stabilization with its extended wing tips while the inverted trailing edge reduces drag. For boaters looking to get on plane in half the time, reduce bow rise, eliminate chinewalking, stop porpoising and cavitation, while at the same time allow for maximum top-end speed and increased fuel efficiency. Does not fit Volva Penta Engines w/exhaust thru the anti-cavitation plate.All No-Drill StingRay Hydrofoils have the patented No-Drill Technology designed into the hydrofoil and DO NOT need any type of adapter or additional pieces.