5PCS Iron electroplating Wheel Shaft Motor Hexagonal HEX Coupling Coupler length 12mm + 2 spanners wrench 3MM *FD426X5+2 Product Description Iron electroplating 3MM Shaft Motor Flexible Wheel tyre Coupling Coupler Please favor the model that you just need: 3MM 4MM 5MM 6MM Features Material: Iron electroplating (rust-proof) (We have one other Brass kinds,if you need,plesase seek it in our store or contact us) High hardness Resistance to corrosion Total Height: 17-18mm(cylinder height=12.5mm) Outer diameter of cylinder=12.7MM Length OF SIX SIDE:7mm Hexagonal edge to edge distance: 12mm Screw of side face:3MM Screw Of Hexagonal middle hole: 4mm Package 5PCS X Hex coupler(3MM) 2PCS X Wrench 10PCS X Screw