Mercury - Lab Finished Revolution 4 Racing Propeller - 3-Blade - 150 to 450 HP and 450R HD Gear Case Outboard - Up to 600 HP Sterndrive - 14.6 Dia. - 24 Pitch - 48-8M0106544 The Lab Finished Revolution 4 is designed to increase speed for lightweight Center Console boats. Eligible for Joy Stick Piloting outboards. Expect to gain 300 rpm over the stock Rev 4. The Revolution 4 propeller fits 150 to 400 HP and 450R HD gear case Mercury outboard models, up to 600 HP sterndrive.