The Nintendo Super System is Nintendo's arcade version of the Super NES, like the Playchoice 10 was to the NES. They run basically the same hardware as a Super NES (though has 3 cartridge slots), plus an additional processor for the menu, coin-op, etc.
The Nintendo Super System PCBs use the separate APU module, like the early Super NES systems. When the boards get moved around, repaired, etc... the standoffs and screws tend to get misplaced, and are commonly missing on these, leaving the APU to be supported only by the connector (if the APU isn't missing completely).
This thing is a set of replacement standoffs for the APU. There are the original replacements, which are just tubes of the correct size to use with screws... and a clip version, which snaps in place, requiring no additional hardware. On my printer, the clip didn't come out perfect (I didn't use support material), but it worked well enough, and snapped tightly in place.
There are 3 sizes of tubes... the two short corners use the medium length, the tall corner uses the the tall length. The short tube is used as a spacer on top of the APU on the corner nearest the CPU. The spacer isn't used with the clip, so there's only a medium and tall clip version.
The Sketchup file is also included in case you want to make any changes to the design.
The tube standoffs are easily printed with any material at any layer height.
The clip standoffs should be printed laying down, with the slots facing vertically (like shown in the picture). They are small, and need the detail, so a shorter layer height should make a better clip. They also have to slightly flex, so ABS (or other somewhat flexible material) is probably a better choice than PLA or other stiffer material.
Note that the clip heads are different lengths on the medium clip version. The short side clips into the (thin) metal of the APU, and the long side clips into the (thicker) PCB.