FB – factory balanced propellerGF 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 diameter10″ / 254mmPropeller pitch6″ / 152mmHubthickness1/2″ / 12.7mmShaft diameter1/4″ – 5/16″ / 6.35mm – 7.94mm *Propeller Weight0.74oz / 21gDirection of rotationNormal / TractorMaterialGlass Fiber R CompositeColorBlack