Summary It is a large screw and a holey box to screw it into. The threads stick out of the sides of the box, and it makes for a fun fidget toy. I made it using OpenSCAD, and printed it on a Printer Bot Play. I found that scaling the cross-section (pre-extruded outline) of the screw down to 95% of the size of the hole in the box worked best. The uploaded files should be properly scaled.