The Bennett Marine A1109 Piston with O-Rings fits Classic Hydraulic Trim Tabs. Bennett Marine continues to lead the way as the largest manufacturer of durable hydraulic and electric trim tab systems for a variety of boat styles and sizes. More than 50 years in business, millions of trim tabs sold, and unmatched customer loyalty and satisfaction, we can proudly say that we've learned how to make extremely reliable products that outperform the competition. That's why most of the best boat builders in the world use Bennett systems as standard equipment.