Riser blocks for gridfinity designed to allow routing cables underneath and around other gridfinity modules.
The 21mm tunnels are large enough to push USB A connectors and barrel jacks thru. However AC wall plugs will not fit (e.g. most NEMA connectors) nor will larger IEC connectors (like the ever immortal C13 connector popularized by PC power supplies).
Originally motivated when gridfinitizing a battery charging cabinet.
Provided many likely model sizes for convenience, but if you need other dimensions, the OpenSCAD model is available here: https://github.com/jcorbin/gridfinity-risers
Made based on modules from https://github.com/vector76/gridfinity_openscad .
I've also made a standalone baseplate variation of this block if you don't want to print out a base frame.