Product Sizing Chart (includes XL)
| Tiny | XXS | XS | Small | Medium | Large | XL | |
| Bill Width | 3.35" | 3.85" | 4.5" | 5.25" | 5.9" | 6.4" | 7" |
| Head Width | 2.5" to 3.25" | 3" to 3.75" | 3.5" to 4.25" | 4" to 5" | 4.5" to 5.75" | 5.5" to 6.25" | 6" to 6.75" |
| Neck Size | 8" to 10" | 10" to 12" | 12" to 15" | 14" to 16" | 15" to 18" | 17" to 21" | 20" to 25" |
| Approx. Weight | about 5 lbs. | 7 to 14 lbs. | 13 to 25 lbs. | 22 to 45 lbs. | 40 to 65 lbs. | 60 to 100 lbs. | 100 lbs. and up |
| Size | Popular Breeds | |||||
| Tiny | Chihuahua (smaller), Maltese (smaller), Pomeranian (smaller), Toy Poodle, Yorkshire Terrier | |||||
| 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 |
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| 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 (smaller), Labrador Retriever, Pit bull, Rottweiler, St. Bernard (smaller) | |||||
| XL | Bernese Mountain Dog (larger), Great Dane, Labrador Retriever (larger), St. Bernard (larger), Pit bull (larger), Rottweiler (larger) | |||||