Small: 6.94" x 4.125", with black .38" wide collar, adjustable 10" to 16.75"
Medium: 9.13" x 5.5", with black .63" wide collar adjustable 10.56" to 16.75"
Large: 12" x 7.3" with black collar .79" wide, adjustable 12.5" to 20.5"
X-Large: 14.5" x 9" with black collar .98" wide adjustable 15.5" to 23.5"