GoolRC 2 Pairs 6045 6*4.5 Carbon Fiber Propeller Prop CW/CCW for QAV250/280 H250 Multirotor Quadcopter Material: Carbon Fiber Suit for: QAV250/280 H250 Multirotor Quadcopter. Center hole diameter: 5mm Screw pitch: 4.5 Length: 6.0 inch