The Total Pet Healthâ„ Elizabethan Collars prevent pets from licking and annoying wounds. Flexible plastic to help pets heal from injuries faster, preventing them from licking injured areas for dogs and cats Material: Polypropylene plastic Fits collar size: XS – 5-1/2"-9-1/2'' Small 6-1/2"-12'' Medium – 8-1/2"-14-1/2'' Large – 11-1/2"- 18'' String gauze (not included) through oval holes close to neck to secure E-Collar pet's neck."