It has a column with thicker walls than stock with bolts via four bolts to the bed. It's much superior. You have to use shims to adjust both X and Y alignment. You can view the two adjustment separately, and simply sum the shim on the shared corner. For example, if you need 0.001" of shims on the front of the column and 0.002" of shims on the right of the column, then the left back corner wouldn't have any shims, the left front corner would have a 0.001" shim, the left right corner would have a 0.002" shim, and the right front corner would have a 0.004" shim.
I upgraded the mounting bolts to grade 12.9 M8x40 socket head cap screws which are 5mm longer and have more thread engagement. I used a torque wrench to tighten the bolts to make my readings consistent between adjustments, using 16.5 ft/lbs (200 in/lbs) with silver anti-sieze on the threads.