When I needed to create a strap for my growing collection of masks and helmets, I was looking for the ideal way to create an adjustable strap. A well known internet delivery company wanted too much for these, so I created my own!
All you need is some elastic tape and a glue gun. From there, you can create your own elastic strap that can be adjusted.
Included is a print file for the A1 mini.

I tested the infill from 5% to 25% and each was sufficiently strong enough to hold the strapping in place and not buckle.

Re-works welcome.