... 2.High microstep,high torque 3.broad voltae range 4.wide output current range:0.3-8V Characteristics: ... 1/2,1/4,1/8,1/16,1/32,1/64,1/128,1/2561/5,1/10,1 ... high or working current over 2.7A, fix the module on big metal shell , or use axle flows ... fan dispels the heat, to make the module run reliably for a long time.2, Half ... A)1.31.82.32.73.23.74.24.5 3,Full current or half current choice:SW4: ...