It's a plug for the vacant insert holes on your snowboard.

You know how at the end of the day on the snow, there's snow, dirt, or other junk accumulated in the vacant mounting holes?  It's not a lot,  but when it eventually thaws, the water is going to sit there, possibly corroding the inserts, or dripping to the floor.   I prefer having this all gone before the snow toys are put away for the day , much less the season.  

Tape usually ends up  peeling off ½ way through the season, and stickers develop holes from the bindings… Enter - a flush mounted grub screw which will cover the holes, and (hopefully) prevent water and dirt intrusion in this space.  Note, I did try looking online first, but only found an item that too short.  

This works best when printed in TPU. It's so small, that you don't even need to worry about infill - it's a solid piece.  As a bonus, I added a cavity for a size 00 Philips head to easily install the plugs.