This is The Latest in 4-stroke technology. Twin impeller for Sea Doo models gives you the ultimate performance. With added acceleration and gains in top speed performance.Concord - The Power Torque Series With features like a large blade area and a unique geometric blade design, the SOLAS Concord Impeller delivers remarkable thrust and extraordinary efficiency. As four stroke technology becomes mainstream in the PWC world, the Concord design truly enhances the engine characteristics, not only delivering incredible acceleration but excellent top end performance. From water skiing to high speed cruising, this technologically advanced power torque design with its radial leading edge will offer everything you could ask for in an impeller.