Fits watches: 38mm, 40mm, 41mm, however, they have been tested to fit all sizes of Apple watches and all series, the larger face sizes will have a tiny gap on the sides noticeable only if you're looking for it!
Fits wrist sizes up to 7.1 inches. If you do not have a measuring tool at home or are unaware of your wrist size, use this printable measuring tape to measure your wrist.