Tough, durable nylon, this collar is easy on dogs with long hair. No snag on dogs fur. The 8mm collar is about the size of a pencile. This collar is available in the following colors Red Stripe, Blue Stripe, Black Stripe and Pink Stripe. For correct size please measure your dogs neck and add at least 2 inches. The size of this collar includes the rings from end to end. The 8mm choke collar is available in Sizes 12, 14, 16, 18 and 20.