The muzzle itself fits really well! However, there have been 2 problems with it.First, there's no way for a dog to drink water when using this muzzle, which is a problem when training. They need water. The work around, I got a hampster water bottle and put it through the muzzle for the dog. Second issue is the metal rivets that hold the muzzle together are AWESOME, very secure, but they are rusting on the inside of the muzzle. Obviously, the saliva is causing this, but I can't/would never use a See full review