10PCS 2mm to 3.17mm Brass Shaft Coupling, L20 x D9 Set Screw Rigid Coupler Motor Connector for DIY, Small Motor, RC Boat Car Airplane

["Size: Total Diameter 9mm/0.35inch Length 20mm/0.79inch, Bore Diameter 2mm to 3.17mm/0.08inch to 0.125inch","Shaft Coupler Material: Rigid coupling material is brass, anti-corrosive, high temperature and oil resistance, ensuring long-term use","Performance: Rigid motor shaft coupler fixes the shafts by tightening the screws for more efficient, responsive, stable and low-inertia power transmission between the two shafts","Wide Range of Usage: Rigid coupler is suitable for 38D printers, robots, motor accessories, DIY model, CNC machines, step motors and more mechanical drive industry","Packing List: 10 PCS Small Rigid Set Screw Brass Shaft Coupler, 2 PCS L Hexagon Wrench, 40 PCS M3 Set Screws"]