My muzzle-hating pony took really well to this, and has been happy and settled wearing it, even for longer periods of time. I was surprised how quickly he accepted it, as he had been quite distressed in other bucket style muzzles in the past, so this is the first time I have been able to use one on him.
I'd advise using the size guide to measure for the correct size, as my pony wears a cob size headcollar, but required the large/oversize muzzle!