This is a hard to print testfile!
often you don't know if your printer is ready for complex files. with this file you have an easy option to check problematic printing/slicing stuff.
does your printer challenge this ultimative part?
check it out and get (almost) instant results.
these test are included in this tiny file:
size: the object is 4x50x50mm (baseplate)
hole size: 3 holes (3/4/5mm)
Nut size: M4 Nut should fit perfectly
fine details: pyramide, cone, all numbers
rounded print: wave, half sphere
minimum distance between walls: 0.1/0.2/0.3/0.4/0.5mm
overhang: 25°/30°/35°/40°/45°
bridge print: 2/3/4/5/6/7/8/9mm
surface: all the flat parts