RC Airplane Helicopter Ship 3.17mm to 3.17mm Motor Shaft Coupling Product Name : Motor Shaft Coupling;Type : 3.17mm to 3.17mm/0.12" to 0.12" Total Size : 2 x 0.9cm/0.79" x 0.35"(L*D);Thread Dia : 2mm/0.08" Main Color : Gold Tone;Material : Brass Weight : 5g Package Content : 1 x Motor Shaft Coupling4 x Install Screws