Features 1. Standard for 40PIN GPIO extension header, supports series boards, Nano 2. Onboard dual HR8825 motor controller IC with built-in microstepping indexer, drives two stepper motors, easy to use 3. 6 available microstepping modes, configured with the DIP switches: full-step, half-step, 1/4-step, 1/8-step, 1/16-step, and 1/32-step 4. Adjustable motor drive current via potentiometer, maximum 2.5A current output Overview Stepper Motor HAT (B), alternative solution of Stepper Motor HAT, drives two stepper motors, up to 1/32 Microstepping, for 3D printer, sculpturing machine, mechanical arm... Protection features: Overcurrent Protection (OCP), Thermal Shutdown (TSD), VM Undervoltage Lockout (UVLO) Integrates 5V regulator, allows providing power to Onboard multi connector options for stepper motors in different specifications Specifications Motor controller: HR8825 Motor drive voltage: 8.2V~28V Motor drive current: 2.5A Logic voltage: 3.3V Mounting hole size: 3.0mm Dimension: 65 x 56mm color: blue Material: PCB Package Contents: 1 x Stepper Motor Expansion Board (B) 2 x RPi screws pack 1 x Aluminum heatsink Only the above package content, other products are not included. Note: Light 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.