Features: This is a high-quality, high-power, cost-effective Motor Driver High current 4.5A, high voltage 45V, output short circuit protection, superior performance! automatic half current function. And a semi-automatic flow switch, easy to use. the use of high-speed optical coupling 6N137 ensure high-speed without losing step. Used to increase the heat sink, good heat dissipation. Using common anode input mode, there are two input terminals, wiring more convenient. For 4.2A 42,57,86 within the two-phase / four-phase / four-wire / six-wire stepper motor. Automatic half current function. Low-pressure shut-off, overheating parking and over-current protection circuit, short-circuit protection Specifications: Type: TB6600 Operating voltage DC 10V-45V. DC32V Size: 8 x 5 x 3.5cm Net Weight : 118.3g Package includes: 1 x Motor Driver