The 2 most common reasons to use the ring cutters are fracture and laceration. Even if the bone isn't broken the swelling can be a problem. The worst case for laceration is a "peel down" injury. Happens when you slip in the shower and reach to grab onto something and end up with your ring caught on the shower head and your body hanging. You can also get caught in the basketball net/hoop. That's why athletic trainers carry them. You won't need them often, but when you do, you'll want them. The only FAK I keep them in full time is the large "camping/group outing" kit.