4 full H Bridges: TB6612 chipsets provide 1.2a ( 3A) per bridge with thermal turn-off protection and internal protection diodes. Can run a 4.5VDC motor up to 13.5VDC. Up to 4 two-way dc motors with a separate 12-bit speed option (about 0.02% resolution) Up to 2 stepper motors (unipolar or bipolar), single coil, double coil, staggered or micro-stepping. The motor is automatically disabled when the power is turned on Large 3.5mm terminal block connector for easy connection of wire (18-26awg) to power supply Polarity protection 2-pin terminal block and jumper are connected to external power supply for separate logic/motor power supply Fully stackable design: 5 addresses to select jumper pads means up to 32 stackable wings: this is 64 stepper motors or 128 dc motors. Product size: about 50 x 25 x 8mm / 1.73 x 0.62 x 0.62inch Color: As Shown Material: Plastic+Metal Package Contents: 1 * board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.