A Box for the Gridfinity system to hold your caliper (and some pens). The system is by Zach Freedman and I link the Baseplate further down. It's a 6x2 component (~252 x 84mm) and is around 21mm high. It has place for one caliper an some pens. Baseplate link: https://thangs.com/designer/models/3d-model/60925?part=2d4ec278-7c90-4bc3-a2b1-8eb61204a670