Holds a 3/8" or 9.5mm shaft dial indicator on the extruder head for bed leveling in the Anycubic 4Max Pro. There is a spare threaded insert (M3x6 bolt here) on the left hand side of the head that can accept this holder. It is not meant to be left on the machine, so you can print it in PLA or ABS. The dial indicator slips into the holder, turn it to fit up between the rails, screw it on, go about your bed leveling... The dial may not face you but it should be sturdy.
Printed without any compensations or support. Only a brim is needed to hold it to the bed.