This is a plain 30mm square base, suitable for use in wargames that require this. Absolutely nothing special about this, but I couldn't find one when I wanted to make some and decided to upload this here for the next passer-by.
Printed on an Ender 3 V2 in PLA at 20% fill.
No supports required, used 2 g of material at these settings.
30mm_base.stl | 684.0B |