We bought 3 of these colars, 2 large sized and 1 medium sized. The medium sized is great, fits well. The large ones, however, are terrible: they constantly come completely undone. The loops that should be keeping the strap done up, do not work, they constantly slide around and thus the strap comes out of them and the next you know the collar comes off completely. Would receommend the clip on tags that are available for airtags and just clip it to the existing collar.
