Super Strong Dual-Actuator Trim Tabs built for demanding commercial and sport applications. Super Strong Trim Tabs are built extra-rugged for sport fishing, large cruising and commercial boats. Blades are made of heavy-duty, 7-gauge (4.6mm) 304 stainless steel. Hinges rotate on an extra-strong 3/8" diameter hinge pin. Robust construction includes high-impact upper mounting brackets with mechanical gland cable seal and welded-on stainless steel lower brackets. Stainless steel mounting hardware includes beefy stainless steel 5/16" upper and 3/8" lower mounting bolts. Trim tab planes come with a 3 3/4" diameter sacrificial anode installed. The completely flat blade design reduces spray and produces a clean, dry ride. A minimum transom height of 11" is required for installation. About the actuators Lenco electric actuators are built around a proven-dependable ball screw design that is twice as powerful as comparable hydraulic models. More power is complemented by an instant response to helm commands, which means you can correct your boat's trim angle much faster than with hydraulic designs. Actuators are (of course) fully submirsible, with a sealed design and "plug and play" waterproof Deutsch connections, which also help to make installation easy.