I've left three different versions of the strap holder
The differences are in the height and with of the holder
1 Is 6mm high, and has a width of 4,5mm
2. Is 5,5mm high, and has a width of 4,5mm
3 Is 5,5 mm high, and has a width of 5mm
I would recommend printing all three and see what you like (they won't use up your spool that's for sure!). Personally, I would go for one of the 5,5 mm high ones. They are a bit more difficult to get on the strap, but they sit better. Also, have the tooth facing towards the forearm, it will grip better that way.
You will probably need to use tpu or any other bendable filament unless you can somehow print it in place over the strap using the pause feature.
I used support, but I don't know if it is needed. I also used one raft layer, this both to get better adhesion, and also my slicer was acting up with the first layer, using one layer of raft (0,1mm contact distance) fixed both issues. Print by objects.
The author marked this model as their own original creation.