Designed to fit standard sized jewelry bits, heavy and stable enough to not topple over easily but also hollow bottom to save on resin. Holes have a diameter of 2.6mm, standard bits are around 2.33mm. Have printed on Elegoo mars 3 pro with around 15 heavy supports and the rest light supports with standard grey resin. Designed in Rhino, uploaded as STL and 3dm. Included is a Chitubox supported version, results may vary on printer and resin type.