This is a mashup of two other designs. Antosop's simple tool holder for the X3D AMS Riser by DutchWorkX3D, and a pegboard digital caliper tool holder by Eric M Boyd on Thingiverse.
ATTENTION: The hex plug on this design has been scaled up to 101% to match my riser which had to be scaled up to allow the glass to fit inside of the riser. If your riser is printed true to scale this holder will be very tight if it fits at all.