Petite - 3/8" wide, fits 5" - 9" necks. Small - 1/2” wide, fits 8” - 12” necks. Medium - 3/4” wide, fits 11” - 16” necks. Large - 1” wide, fits 15” - 22” necks. X-Large - 1” wide, fits 19” - 29” necks.