The collar's wearing size (i.e., its measured inner diameter) is S (15-19.5 inches), M (18.5-22.5 inches), L (20.5-24.5 inches). Kindly measure your dog's neck girth and leave space for two fingers to choose the right size. And kindly note that the significant thickness of the product results in a huge difference between flat measurement and wearing measurement, so please select the size strictly according to the collar's inner diameter we provide Spiked Leather Dog Collar – Premium Handmade Genuine Leather, 2.2-Inch Wide, Bold Protection and Stylish Design, Ideal for Powerful Breeds Designed for powerful breeds like Pit Bulls, Rottweilers, Dogo Argentinos, and American Bullies, this luxury spiked dog collar is a perfect blend of style, strength, and protection. Handcrafted from premium genuine leather, this collar features a robust 2.2-inch width (5.5 cm) that ensures comfort and support for your dog’s neck, making it ideal for active, muscular dogs. Key Features: Premium Genuine Leather: Soft on the inside and tough on the outside, providing ultimate comfort and durability. 2.2-Inch Wide Design: The extra width ensures proper neck support, especially for medium to large breeds, helping to prevent discomfort or irritation. Spiked Protection: The striking spikes not only enhance the look but also offer an additional layer of protection, deterring unwanted encounters. Perfect for Powerful Breeds: Tailored for strong and fierce-looking dogs like Pit Bulls, Rottweilers, and American Bullies. Available in Multiple Sizes: Choose from S (16.7-20.6 inches), M (19.7-23.6 inches), and L (22.6-26.6 inches) to fit your dog perfectly. Be sure to measure your dog’s neck with a soft tape measure, allowing space for two fingers to ensure comfort. Whether you're looking to make a statement or ensure your dog’s safety and comfort, this spiked leather collar is the ultimate accessory for your fierce companion.