The Speedbox is designed to let the CR-10Pro printer use the Nimble V1 and V2.
It is a belt-driven system that speeds up the drive cable by a factor 3. This allows the stepper driver on the control board to be able to handle the speed needed for the NImbles.
It can also be used to allow other slower control boards to still use the Nimbles.
You will need to print the housing, files are included in the order and can be downloaded right away.
What is in the box: