Waterproof, stink-proof, and reflective, the Headwater Collar from Ruffwear is perfect for dogs that frequent the water or live in wet climates. The collar's coated webbing is flexible, yet waterproof and non-absorbent, solving the wet, smelly collar problem. Reflective pattern is easy to see in low-light conditions. Silicone tag silencer minimizes tag jingle. Measure around the neck where the collar would comfortably lie. The Medium collar measures 14-20". and the Large is 20-26". Width of the collar is 1".