Features Compatiable: this Stepper Motor Driver Use removable A4988 or DRV8825 compatible stepping driver Mainly Function:The extension board can be used for engraving machine or 3D printer driver Single Channel Support: Compatible with GRBL 0.8. Open‑source firmware , converting G code command into stepping signal PWM spindle and direction pin, 4 shaft support (X, Y, Z, A ‑ you can copy X, Y, Z or use pin D12 and D13 customize firmware perform complete shaft 4) Match Kit: Compact design, stepping motor can connect 4 pin connectors or be soldered Specifications: CNC Expansion Board: Version: V3.0 Color: Red Size: 68 x 53 x 18mm / 2.67 x 2.08 x 0.7" Voltage: DC 12V to 36V (only DRV8825 driver can handle up to 36V, so please consider voltage for power supply) 4pcs A4988 Driver: Color: Red Size: 20 x 15mm / 0.78 x 0.59" Thermal Shutdown Circuit: Yes Cross Current Protection: Yes Ground Fault Protection: Yes Short Circuit Protection: Yes Compatible Logic Voltage: 3.3V and 5V Five Step Modes: Full, 1/2, 1/4, 1/8 and 1/16 Mix with slow current attenuation model. Internal UVLO and low RDS (on) output. Automatic current attenuation mode Detection/Select. Phase-in rectifier, low power consumption. Warning: Connecting or disconnecting stepping motor while driver is powered on might damage driver. 4pcs Heat Sinks: Size: 8 x 8mm / 0.31 x 0.31" Color: White Package Includes: 1 x V3 Extension Board 4 x Drivers 4 x Heat Sinks Package List