1U Eurorack Blank Tile (Pulp Logic format)

This is the standard 1U “tile” size as defined by Pulp Logic (spec here). 

There are two standards for 1U size eurorack modules: Pulp Logic and Intellijel. They're more or less incompatible. Whoever you bought your 1U rack from will be able to tell you which one you have.

These print super fast on 0.25 layer DRAFT mode on my Prusa MINI+.