X-Small: 1-10 Pounds
Head Strap and Frame: 5-13"
Chin Strap: 3-7"
Breed example: Chihuahua, Pom
Small: 9-25 Pounds
Head Strap and Frame: 12-20"
Chin Strap: 4-8"
Breed example: Beagle, Westie
Medium: 20-60 Pounds
Head Strap and Frame: 15-25"
Chin Strap: 5-11"
Breed example: Dalmation, Border Collie
Large: 50-100 Pounds
Head Strap and Frame: 18-30"
Chin Strap: 6-15"
Breed example: German Shepherd, Labrador Retriever
X-Large: 100+ Pounds
Head Strap and Frame: 22-45"
Chin Strap: 11-26"
Breed example: Large Rottweiler, St. Bernard