USB Controller Board -a4988 stepper motor driver module board for cnc 3d printer + red heat sink Highlights generic brand a4988 stepper motor driver module board for cnc 3d printer + red heat sink Description: Low output RDS (on); Automatic detection / selection of current drop mode. Slow current mixing and decay mode; Low power dissipation synchronous rectification; Internal UVLO. Thermal shutdown circuit, cross current protection, ground fault circuit and load short circuit protection. Five optional modes: full-step, half-step, quarter-step, eighth and sixteenth step. 3.3 and 5V compatible logic supply; Widely used in 3D printers and small CNC machines. Specification: Size: approx. 15.3 x 20.3 x 10.9 mm Package includes: 4988 stepper motor driver 1 piece heat sink