Performance Propellers for Model Airplanes - GF Series FB - factory balanced propeller - for more information click here 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 7" / 178mm Propeller pitch 4" / 102mm Hub thickness 5/16" / 7.9mm Shaft diameter 3/16" - 1/4" / 4.76mm - 6.35mm * Propeller Weight 0.26oz / 7.4g Direction of rotation Normal / Tractor Material Glass Fiber R Composite Color Black