This is a Dingo-style sleeve mount for your bike forks. It has a 53mm ID (for the Yamaha 53.2mm forks, if should work on bigger diameter forks too, just tighter). I use this on my 2019 YZ250F fork so I can put OHV rego on the forks without making it permanent (Good if you need to service your forks).

I printed with PETG, 0.2mm layer height, 100% infill. A brim might be a good idea, contact area is small.