Doel-Fin Hydrofoils improve hull stability and engine performance. This is the easiest to install aftermarket performance product you`ll ever use. Works on all outboard motors and stern drive units from 5hp and up. Smoother turns, lower planing speeds and less bow rise for increased overall safety. Save up to 30% on fuel consumption. Lower planing speed is great for wakeboarding, tubing and beginning water skiers. Faster out-of-the-hole times. Simple 15 minute instalation; hardware included. Over 25 years` worth of testimonianls and 1 million boaters agree that Doel-Fin delivers. Balanced Performance, Doel-Fin was designed by an aeronautical engineer to produce maximum lift while minimizing drag. Creating lift in the stern compensates for motor weight which in turn produces a "power steering" effect, lower planing speeds, better fuel consumption, faster out-of-the-hole performance and lower bow rise angles.