Fastback straps are designed to be worn on a wide range of wrist sizes. To be sure our strap will fit your wrist, measure your wrist size where you usually wear your watch. If your wrist measures 15-20 cm (6-8 inches), all good! You'll be able to wear a MOT1ON watch by adjusting the strap to one of the nine integrated positions. If not, well, you have the possibility to pick our metal straps that offer a bigger size. We are also working on extending our sizes, but it's not ready yet.