Bobby's collar is thinner than most collars out there. His collar is W16.5mm x D2.5mm. 

The print came out great. AirTag fits snugly into the hoop and is removable. I purposely had the width of the claw made tight cause I want to make sure the case would not move around the collar. So you'll have to slide one end in and deftly force the other in.

Printed with Tree Hybrid in PETG.