Not sure of your ring size? This adjustable pocket ring sizer are easy to use. You will be able to find your or your significant other's size in a few seconds! It works like a zip tie, except it doesn't get stuck on your finger! it is reusable, too! It's small and can be stored flat with your jewelry for future use! Just slip it on your finger, adjust to a comfortable fit and read the indicated size. Each sizer comes in its own envelope printed with easy instructions. Measures in US whole and half sizes 1-17.