The double speed system adopts super hardness steel and is made by CNC precision machining. The movable tooth passes through the weight reduction opening to facilitate discharging the powder. All steel products are well treated by HRC heat treatment. It is the best choice to replace the original plastic parts Gear:43T/47T and 18T/22T Shaft Length:56mm、Dia:5mm Gear :5mm*Dia49mm,5ⅹ45mm,7x20mm and 7ⅹ24mm