XXS - Bill Width: 3.85" - Head Width: 3-3.75" - Neck Size: 10-12" - Approx. Dog Weight: 7-14 lbs
XS - Bill Width: 4.5" - Head Width: 3.5-4.25" - Neck Size: 12-15" - Approx. Dog Weight: 13-25 lbs
Small - Bill Width: 5.25" - Head Width: 4-5" - Neck Size: 14-16" - Approx. Dog Weight: 22-45 lbs
Medium - Bill Width: 5.9" - Head Width: 4.5-5.75" - Neck Size: 15-18" - Approx. Dog Weight: 40-65 lbs
Large - Bill Width: 6.4" - Head Width: 5.5-6.25" - Neck Size: 17-21" - Approx. Dog Weight: 60-100 lbs
Popular Breeds Size Guide:
XXS:Brussels Griffon (smaller), Chihuahua (larger), Italian Greyhound, Jack Russell (smaller), Maltese (larger), Mini Dachshund, Papillon, Pomeranian (larger)
XS: Boston Terrier (smaller), Brussels Griffon (larger) Cavalier King Charles Spaniel, Cocker Spaniel (smaller), French Bulldog (smaller), Jack Russell Terrier (larger), Pug (smaller), Shiba Inu (smaller), Shih Tzu (larger) West Highland Terrier
Small:Australian Shepherd (smaller), Beagle (smaller), Border Collie (smaller), Boston Terrier (medium), Cocker Spaniel, French Bulldog (medium), Pug (larger)
Medium: Australian Shepherd (larger), Beagle (larger), Border Collie, Boston Terrier (larger), Boxer, Doberman Pinscher (smaller), French Bulldog (larger), Golden Retriever (smaller), Greyhound, Labradoodle, Pit bull (smaller)
Large: Akita, American Bulldog, Bernese Mountain Dog (smaller), Cane Corso, Doberman Pinscher (larger), English Bulldog, German Shepherd, Great Dane, Labrador Retriever (larger), Pit bull (larger), Rottweiler, St. Bernard (smaller)
