Casual Canine® Bad to the Bone Harnesses feature padded nylon for comfort and a "Bad to the Bone" disc charm accent. The fun theme of our exclusive Casual Canine® Bad to the Bone Harnesses let dogs show their true colors. Reflective screen-printed design combines fashion and safety. Comfortable, padded nylon is easy to wear. Sturdy, fully-adjustable Harnesses have quick-release plastic buckles. Material: Nylon with plastic buckles and nickel-plated D-ring X-Small is 3/8"W and fits chests 8"-14", Small is 5/8"W and fits chests 14"-20", Medium is 3/4"W and fits chests 20"-28", Large is 1" W and fits chests 28"-36".