This from Hobie: "This third generation rudder the EPo3 combines the original shape of the EPo2 rudder with an improved trailing edge. We developed the EPo3 rudder blade as the next generation performance rudder blade for the 14, 16, 17, 18 and 20. With this proven foil shape and a fine trailing edge, the EPo3 offers reduced cavitation with smoother, more forgiving control. The EPo3 rudder is stiff where it counts due to its hand laid fiberglass construction incorporating extra cloth for longitudinal stiffness. We have placed extra glass in all the right places to ensure that it is tough enough for the most demanding sailors using extreme mast rake. You will experience supreme performance and handling not found with other rudder blades. White EPo3: gucci looks, stiff and light weight."