Feature: 1. The for R3 kit is fully equipped, which makes the kit quite practical and convenient for daily use. 2. The stepper motor can be connected or soldered in place via a 4‑pin for Molex connector, and can work at DC12‑36V. 3. The product supports 4‑axes, in which X‑axes, Y‑axes, Z‑axes and A‑axes can use pins D12 and D13 to copy X, Y, Z with custom firmware or make a complete 4th axes. 4. High quality material can make sure the durability and stability of the product. 5. The package includes 4 4401 motors, 4 motor wires, 1 USB cable, 4 A4988 driver, 1 for R3, 1 CNC expansion board, 1 pin, 4 heat sinks and 1 English user manual. Specification: Item Type: For R3 Kit Compatible with GRBL 0.8c 4-Axex Support. Package List: 4 x 4401 Motor4 x Motor Wire1 x USB Cable4 x A4988 Driver1 x For R31 x CNC Expansion Board1 x Pin4 x Heat Sink1 x English User Manual Note: Currently only the Pololu DRV8825 driver can withstand voltages up to 36V, so please consider the operating voltage when supplying power to the development board.