Not sure of your ring size? This reusable + adjustable ring sizer can be mailed to you before placing a made-to-order ring. These sizers indicate whole and half numbers for bands that are roughly the same width as the sizer. Yes, band width matters. TO USE: It's quite simple... Slide onto your finger like a tiny belt and tighten until comfortably snug. (It should slide over your knuckle with a little resistance, but not feel 'pinchy'.) Then read the number (or dash) that aligns in the middle of the magnifier. If it's a dash mark instead of number, that just means you're a half size. For example, if it aligns on a dash that is between 10 and 11, that means your size is 10.5. TIP: You may want to size the finger at different times of day, since fingers can shift slightly with temperature, activity, and swelling. Please Note: This listing is for the ring sizing tool only, and depending on inventory, you may receive a variation of the one shown. A ring is not included.