Carhartt Dog Collar I Built of rugged construction and reflective triple-needle stitching for dogs that work 24/7 Quality You Can Trust I Ultra-durable collar is up for whatever task comes your dog’s way. Constructed from durable nylon webbing with duck canvas weave Low Light Visibility I Reflective triple needle stitch for low-light visibility. Plastic strap keeper and adjuster Carhartt-Strong I Rugged slotted metal D-ring with tag holding capability Sizing I Medium (Neck: 12"- 18" Collar Width: 3/4") Large (Neck: 18"- 26" Collar Width: 1") Measure at the base of the neck. Note: Do not measure too high on the neck as it may result in a smaller than optimal measurement