Reflective Stitching Black Neoprene Comfort Padding Three Adjustable Sizes Metal D-Ring (for Leashes) sizing Size Width Length Small 5/8" Nylon Adjusts to Fit 10" to 14" Medium 3/4" Nylon Adjusts to Fit 14" to 20" Large 1" Nylon Adjusts to Fit 18" to 26"