MASTER AIRSCREW 15 X 6 PROP K SERIESPerformance Propellers for Model Airplanes - K Series Designed for larger 2 and 4 stroke glow engines and electric conversion models. The K series provides great performance and durability. Made of Glass Fiber Reinforced Composite in sizes 12 to 16". Propeller diameter 15" / 381mm Propeller pitch 6" / 152mm Hub thickness 11/16" / 17.5mm Shaft diameter 5/16" - 3/8" / 7.94mm - 9.53mm * Propeller Weight 2.4oz / 68g Direction of rotation Normal / Tractor Material Glass Fiber R Composite Color Black