My son broke his vintage Casio F-91W watch straps. No problem ! I'll print new one in TPU !
The size is 18 mm.
I design this bracelet to be as comfortable as possible. It can fit small wrist. The idea is to print the straps already curved to a mean wearing radius, and make it thin. This is where the honeycomb pattern come to my mind.
You may have to cut and adjudt with sissors...