This Master Airscrew 11x4 Scimitar S-2 Profile Propeller is from Windsor Propeller Company's Profile Series. FEATURES: The Scimitar Series features a high performance Scimitar shape with swept-back, narrow tips & undercambered blades The Scimitar shape generates greater thrust at lower RPM, resulting in less noise Made of lightweight, black, glass-filled nylon Propeller is totally fuel-proof INCLUDES: One 11x4 Profile Scimitar Propeller SPECS:Propeller Diameter: 11" (279mm) Propeller Pitch: 4 Hole Diameter: .244" (6.19mm) REQUIRES: Depending on the engine crankshaft size, the propeller may need to be reamed to a larger size using GPMQ5005 (SAE) or GPMQ5007 (Metric).