Size of collars: large 20-30 inch 30 inch 35 inch medium 25 inch 16-26 inch 36 inch Small 21 inch 26 inch 31 inch 17 inch 32 inch 14 inch 37 inch 22 inch 27 inch 15 inch 18 inch 38 inch 28 inch 33 inch 16 inch 19 inch 39 inch 23 inch 34 inch 20 inch 40 inch 24 inch 29 inch
Use: Police/Military K9 training Walking and daily use For working dogs Search & Rescue All weather Obedience training Training