These custom name tag collars are made exclusively for Outdoor Dog Supply here in the USA. They are made with poly-coated nylon that is water, odor, and rust resistant. These collars have a glowing stripe down the center – they are very bright and only take a few minutes to ‘charge up’ in bright light. They glow very brightly and last several hours. They have tight hole spacing for a better fit on your dog, a D ring at the buckle, and an O ring at the center (that sits at the back of the dog’s neck). There are two sizes: 21″ long and will fit neck sizes of 14″ to 21″, and a 19″ long and will fit neck sizes of 12″ to 19″.