Sizing Information: Small: Made with 5/8" Beta BioThane®️ coated webbing; fits neck 12" - 16". Beta Finish: The Beta BioThane®️ coated webbing is the most flexible and soft. It does not have a sheen and is often used as a leather replacement because it is stronger and more durable. The strength of the material does not come from the coating, but from the polyester webbing inside. Cleaning BioThane is a breeze - just a little soap and water takes dirt and grime right off and the stainless steel hardware won’t rust. BioThane is waterproof, does not absorb odors, and will not mold or mildew. Under normal use, the material does not get tacky or sticky, and remains flexible in cold weather. The hardware on all of our collars and leashes is stainless steel.