I bought this product and it came in just 2 weeks! My dog is a crossbreed of German Shepherd and Malinois. I filled in all of his sizes so it fits him perfectly now. He can freely bark in it and he cannot take it off. And I trust this muzzle 100% that it will not fall down in comparison with the other muzzles that I had. It has many holes for free breathing and it allows my dog to open his mouth and to bark what is extremely useful for agitation work. I paid for a quick-release buckle which is much more convenient for putting on and taking off the muzzle especially in the excited state after training. Thanks again and I will buy from you in the future.