DUBRO 8mm X 1.0mm PROP BALANCING SHAFT This is the Du-Bro 8mm x 1.0 Propeller Balancing Shaft for Multi-Rotor Drones. FEATURES For use with the Du-Bro #499 Prop Balancer, DUBQ0130 Aluminum construction Accurately balances quadcopter props and allows user to eliminate vibration from unbalanced props Clockwise threads on one end, and counterclockwise threads on opposite end