Happy Troller - Large Plate Large Troller: Fits inboard/outboards plus all outboard motors 50 hp and larger. For the Fisherman who thinks he has everything! Slows even big motors down to that 'ever-so-slow' fish tantalizing speed. A significant invention in the sport of troll fishing, Happy Troller® mounts on the anti-cavitation plate to allow fine control of trolling speed. At cruising speed, your boat's stability is enhanced. Locks in 'down' position for trolling. Locks in 'up' position for cruising. Happy Troller is the answer to correct trolling speed. Use it year-round in all boating activities; salt and fresh water. Key Features: * Reduces troll speed in 'down' position * Acts as a stabilizer in 'up' position * Maintains stability in bow-light boats * Smooths out ride in rough water * Reduces porpoising and cavitation * Made of only highest quality stainless steel and marine aluminum; clear anodized aluminum finish * Installs in 15 minutes * Stainless steel mounting hardware and installation & operating instructions provided with each unit