The revolutionary Trol-A-Matic® Trolling Plate lets you operate your motor at a wide range of speeds from very slow to wide-open. Plus, with completely automatic operation and the ability to swing up as speed increases, the Trol-A-Matic marine Trolling Plate has no interference whatsoever. Fiberglass-filled-nylon construction ensures this boat trolling plate has superior resistance to rust and corrosion. Works on most outboards or inboard out-drives 50hp and up. Mounts in minutes. Not for use with Volvo out-drives.