The Outboard Skeg from Skeg Depot will help to keep your boat s propeller from being entangled in water debris or other hazards that your boat may encounter. It is used best with all outboard and inboard engines, as well as stern drives and lower unit applications. The skeg functions as a precise rudder, allowing the motor to steer your boat precisely and safely. Second, the skeg protects your propeller from debris in the water and from going aground. Key features: It protects your prop and drives from harm by cushioning the impact Keeps the boat running straight Specifications: Manufacturer s Part Number: 70-4045 Item Weight: 1 pound 12 ounces net poundage Replaces 70-4045, SY-40-50, S-17, Y45,77-01607 40-50Hp. Thickness 5/16 inches Manufacturer: Skeg Depot Brand: Skeg Depot 40-50 hp. Thickness 5/16