Great product idea that just didn't work out for me. Don't know if I actually just got too large a size (as another reviewer suggested) because there was only one UPC available in the store where I bought them, so I've not seen different sizes. These proved to be too large to go between most of my teeth comfortably, forcing the shaft to bend, and the metal scraped oddly against the teeth it went between. I was afraid that it would damage the enamel. They seemed a little flimsy, and once bent on closely spaced teeth they didn't straighten out very well either. These wouldn't go between my molars or crowns at all, although they cleaned admirably under and around the sides of my bridge. I also found them to be a little irritating to my gums, which can be somewhat sensitive at times. I've used other GUM products that worked much better and was a bit disappointed in this one.