" data-description="Handmade BioThane Martingale collar suitable for sighthounds (such as whippets, greyhounds, Borzoi, Saluki, etc.). These collars are also suitable for similar breeds with a neck as wide as or wider than their head. How does a Martingale Collar work? They are designed to gently tighten around the neck if your dog slightly pulls on the lead. they will not slip over a dog's head. BioThane has many benefits including: Durability: Biothane is highly durable, resistant to wear and tear, making it a long-lasting material for dog collars, leashes, and harnesses.