Our solid brass O rings are perfect for use on pet collars, horse tack, bridles. purse straps, harnesses, belts and other DIY leather craft projects. These metal round rings are often used as bag hardware and briefcase hardware for joining the shoulder strap to the bag or case. These strong O-rings are solid cast for strength and safety as opposed to rings that have a joint which are weaker. The 1 1/2 inch size is the inside diameter measurement so you know how much space is available to accommodate your leather strap or webbing.