The collar has a 100% nylon webbing core surrounded with a cotton fabric re-enforced with lining to improve strength. Collars are made with about 6-10 inches of adjustment (circumference). : • Martingale Collar: Be sure to measure the circumference of your dog's head at the largest part. • Clip Collar: Be sure to measure the circumference of your dog's neck. ( ' /) • XS: 6-10 in • Small: 8-14 in • Medium: 12-18 in • Large: 16-22 in • XL: 20-26 in • Small / Medium: 1.0 in • Large: 1.5 in • XL: 2.0 in Please allow for variations from the photos as no two collars are exactly alike. Pattern placement of fabric may vary. : Please wash collars with like colours and hang to dry. Do not iron. Do not bleach. Do not put in dryer.