How do i put something like this on my mask strap?
DAVID H the mask strap cover is hollow with entry and exit holes on either side. your mask strap will slide easily through these holes.
HAL S Hi,
You remove one end of your mask strap from its attachment point on the mask and slide that end through the mask strap cover making sure that the strap lies flat inside the cover. Reattach the strap to the mask and you are good to go!