This is a simple clip-on beer label holder for Nukatap brand taps. The clip fits snugly without feeling like it's going to snap, and has a ridge on either side to ensure it stays on the cylinder collar. There's a 15-degree slope on the label slot to make it easier to read, and slight wave to the slot to make sure it holds on to any labels you use.

I've only printed it in PETG, as mine will go in a warm garage. I'm sure PLA would be fine. 

It prints fine upside down, though post-processing may be required as any elephant foot will probably close the label slot.

Thanks to Joe B for the idea.

Cheers!