SIZING: CAT: 3/8" width:: 8-12 inches

X-SMALL DOG: 3/8" width:: 6-10 inches

SMALL: 1/2" width:: 8-12 inches

MEDIUM: 3/4" width:: 13-17 inches

LARGE: 1" width:: 15-24 inches

X-LARGE: 1" width:: 17-26 inches