Features:
The expansion board can be used as engraving machine, printer and other drive expansion board.
Compatible with GRBL 0.8. Open source firmware running on for that converts G code commands into stepped .
PWM spindle and direction pins, support 4-axis (X, Y, Z, A - you can copy X, Y, Z or use the pin of D12 and D13 to custom firmware to perform the complete axis 4).
Compact structure, stepper motors can be connected to 4 pin connectors or soldered.
This is a set of disassembled parts and you need basic soldering techniques to solder them together.

Specification:
Radiator Size: Approx 8*8mm
CNC Expansion Board:
Version: V3.0
Voltage: DC 12V-36V (only DRV8825 driver can handle voltages up to 36V, so please consider the power supply voltage)
Board Size: Approx. 68 x 53mm / 2.7 x 2.1in

A4988 Driver Module:
Thermal Shutdown Circuit: Yes
Crossover Current Protection: Yes
Ground Fault Protection: Yes
Short Circuit Protection: Yes
Compatible Logic Voltage: 3.3V, 5V
Five Modes: full, 1/2, 1/4, 1/8 and 1/16
Size: Approx. 20 x 15mm / 0.8 x 0.6in
Mix use the slow current decay model.
Internal UVLO and low RDS (on) output.
Current decay mode automatically detected/selected.
Three-phase rectification, low power consumption.

Package List:
1 x CNC V3 Expansion Board
4 x A4988 Driver Module
4 x Radiator