I was planning on muzzle training my young dog just in case it was ever necessary to muzzle him in an emergency situation (e.g if he became injured and bite-y). He's my first dog, so I wasn't really sure what to look for in a muzzle - but I thought "small and adjustable" sounded like it would fit. It doesn't fit him - he's a Cav x toy poodle (Cavalier sized) and this is far too big. I did not return it because the postage would have pretty much have been the same as the cost of the muzzle (and I wasn't sure if he'd grow into it).
The muzzle is relatively well made, although the webbing straps and clip on the back are surprisingly large given the size of the muzzle. It also smells a bit plastic-y.