The controller has 4 TB6600 stepper drivers, and they produce 2.8 amps per motor (that’s actually through a torque reduction circuit – they are capable of doing up to 4 amps).
The controller comes also in a nice aluminium housing.
The limit switches and probe are filtered through optical isolation (HCPL-817 IC’s)
The usb line between the controller and the computer is isolated to prevent ground loop issues that may otherwise impact signal quality (NEW!)
Connectors for the 4 motors (X axis, 2 for the Y axis Z axis), connectors for limit switches and probe, and for signals to control spindle or laser (PWM – or if the PWM is high enough then it functions as on/off by adding a relais, but 0-10v output is also available), vacuum, mist coolant
See information: https://makerstore.krilano.com/grbl-cnc-controller