As this is supposed to spend most of its time on a pet's collar, I tried a different case design that's flatter and longer. The goal is to get something smaller than the Tractive. So far no effort has been put into details like actually attaching it to a collar or a charging port.

Size is: 76mm x 29mm x 17mm, 34g. That's 3" x 1.2" x 0.7", 1.2 oz

Tractive is 71mm x 28mm x 17mm, 35g. That's 2.8" x 1.1" x 0.7", ~1.2 oz