Maxx Products 10x4.5 EPP1045 Counter Rotating Pair Propellers for RC Airplanes + RC Helicopters Rotor Blade Length: 10 in (254 mm) Pitch: 4.5 inches / revolution 1 Piece Composite Counter Rotating Matched Set Shaft Diameter: 3 mm (0.118 in) Fits GWS gearboxes EPP1045 counter rotating pair