MASTER AIRSCREW 11 X 4 PROP GF SERIESPerformance Propellers for Model Airplanes - GF Series GF Series is specially designed for sport flying and high performance model R/C airplanes with electric motors or glow engines. Made of Glass Fiber Reinforced Composite for strength & durability. Propeller diameter 11" / 279mm Propeller pitch 4" / 102mm Hub thickness 1/2" / 12.7mm Shaft diameter 1/4" - 5/16" / 6.35mm - 7.94mm * Propeller Weight 0.92oz / 26.1g Direction of rotation Normal / Tractor Material Glass Fiber R Composite Color Black