The strap improves the fit of the Oakley A-frame on helmets but it was obviously designed by someone with a tiny head and who stopped after fitting it to his helmet.
As delivered, the strap has is unsuitable for use on Leedom helmets because the tightening loops foul with the strap retainer. The strap is so short that my goggles pressed against my sinuses enough to induce a headache. Clearly, this disappointing design needs work!
In my case I cut the strap, inserted a length of fabric and had a shoe repair stitch the assembly together. Voila! It fits the helmet and fits properly on my face. Too bad Oakley didn't do their homework on this one.