A gearbox to convert the Optimum BF20 vario to CNC. It fits to the X Y and Z axis. It also be used for other machines than the BF20. The item offered is only the gearbox. Also order the separate gear pulley combinations for a complete set. The product is not a direct bolt on, since not all machines have the same axis diameters or bolt spacing small modifications still need to be done. The gears can be lathed down to customers specs and drilled to the desired bore, for an extra charge.