Two OpenSCAD here, one is an evolution of thing 17083 (flat bracelet) and the other adds the texture (knurls in this case).
The inner sizes of the bracelet are 50mm x 60mm and some 32mm tall, the opening is 20mm.
Just print and wear.
If you decide to mess with the OpenSCAD be aware that, at high res, it may take long, too long, before it crashes (I'm jumping from nightmare to nightmare with OpenSCAD lately...)
So, set the res parameter to some high value to get a low res that is able to compile (most probably not able to render).