Features 【Application】: The expansion board can be used for engraving machine or 3D printer driver. Compact design, stepper motors can be connected to a 4-pin connector or soldered. 【Purpose】: Compatible with GRBL 0.8. Open source firmware running on UNO, converting G-code instructions into step signals, precision electronic components manufacturing, and fast response. 【Use】: Simple to operate, PWM spindle and direction pins, 4 axes support X, Y, Z, A, you can duplicate X, Y, Z or custom firmware with pins D12 and D13 to do full axis 4. 【Includes】: 1 x V3 Extension Board, 4 x Drivers, 4 x Heat Sinks, fully equipped, this is a set of disassembled 3D printer parts accessories, you need basic soldering skills to solder the expansion board together. 【Flexible】: Lightweight and compact, the expansion board and driver board kit are easy to move and adjust the installation position, using the removable A4988 or DRV8825 compatible stepper driver, the connection is stable. 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