Large Happy Troller - Idea Developments Happy Trollers are made of aluminum with a clear anodized aluminum finish and contain stainless steel hardware so they can be used in both fresh and salt water. When the trolling plate is down it slows the boat down to trolling speeds. When the plate is up it acts as a stabilizer which reduces porpoising and cavitation, stabilizes bow-light boats, as well as smoothing out the ride in rough water. Idea Happy Troller Plate takes your big motor down to that ever-so-slow fish tantalizing speed! The most effective fore and aft stabilizer that can be installed on a boat. Locked in the Cruise position, the unit eliminates the rooster tail as it forms a hydraulic pressure over and around the propeller, thus providing the optimum environment for maximum thrust. Propeller operates more efficiently (less slippage). Saves fuel during all boating activities (trolling excepted). Increases speed at all RPM settings (trolling excepted). Allows tighter, no-skid turns. Smooths out ride in rough water operation. Pops skiers up in half the normal run. Attaching hardware furnished. The HAP460 large troller fits I/Os plus all outboards 50HP and larger. 1 per package.