A fisherman's answer to correct trolling speed. Trolls the big motors down to the "ever so slow" fish-tantalizing speed. It's "troll fishing" perfected! The Happy Troller locks in the up position for cruising or in the down position for trolling. Installs in 15 minutes. Mounts on cavitation plate (hardware included). Made of the highest quality stainless steel and marine aluminum. Fits 50 hp and larger I/O's and outboards.