6mm Flexible DC Motor Hex Coupling Coupler Copper for RC Model Wheels Product Name : DC Motor Hex Coupler;Material : Copper Color : Gold Tone;Total Size : 30 x 12mm/ 1.2" x 0.47"(L*Max.W) Fit Motor Shaft Diameter : 6mm/ 0.24";Hex Hole Diameter : 3mm / 0.12" Screw Fixed Hole Diameter : 2.5mm/ 0.1";Weight : 20g Package Content : 1 xDC Motor Hex Coupler