... option: shaft , pully, gearbox encoder ,hall sensor , brake, driver, controller 1.8 or 0.9 degree available Model No.Rated VoltageCurrent ... .522.253.613.56SM57HT76-3006ASM57HT76-3006B3311.613.56SM57HT76-2804ASM57HT76-2804B3.22.81.133.618.94SM57HT82- 3004ASM57HT82- 3004B3.631.242241.2182SM57HT82- 5004ASM57HT82 ...