Size: 1
for e.g.: Yorkshire Terrier, Miniature Pinscher
Inner muzzle circumference: 15 cm

Size: 2
for e.g.: Jack Russell Terrier, Toy Poodle
Inner muzzle circumference: 18 cm

Size: 3
for e.g.: Miniature Poodle, Sheltie
Inner muzzle circumference: 22 cm

Size: 4
for e.g.: Border Collie, Standard Schnauzer
Inner muzzle circumference: 23.5 cm

Size: 5
for e.g.: Beagle, Dalmatian
Inner muzzle circumference: 26 cm

Size: 6
for e.g.: German Shepherd, Labrador Retriever
Inner muzzle circumference: 32 cm

Size: 7
for e.g.: Bernese Mountain Dog, Golden Retriever
Inner muzzle circumference: 35 cm