Thanks to this reusable Multisizer Ring Gauge, you can know the size of your finger and order more easily a not adjustable ring. It'is for the French standards and goes from 40 to 76. The Multisizer Ring Gauge is very easy of use. A manual is supplied with it. The Reusable Multisizer ring gauge is working like a belt. Simply push the end through the buckle to form a ring shape. Slip the Multisizer onto your finger. Adjust to give a comfortable fit, checking that it just slip back over the knuckle. When best fit is achieved, please read the indicated size.