Jmt 4 Pairs 10x5.0 3k Carbon Fiber Propeller Cw CCW 1050 Cf Props Cons for Quadcopter Hexacopter Multi Rotor UFO Adopts the high quality 100% 3K all carbon fiber board which imported from Japan improve material Each pair of propellers has perfect dynamic poise and static balancing which balance by manpower Especially improves the air-powered efficiency and aerofoil stability very strong and light weight The Bore Dia is 6.3mm,With 4 pcs washer,2 pcs 5mm,2 pcs 6mm