With a Performance Fin from Uncle Norm's Marine Products on your boat's prop, you can get an edge on the water! The vertical "fins" on the sides of these units cut through the water, decreasing turn radius and boat wander for better slow-speed control and docking ability. The horizontal fluke area across the top blocks the prop from drawing water from the surface, effectivley eliminating ventilation. This lets you get on plane faster and results in a smoother ride! Consider grabbing a no-drill clamp set with your purchase to avoid drilling into your prop and attach the fin in just minutes!