Flexm.
I have GALLS pouches enclosing my 2 6Ps (L.O. Tail cap/round bezel) and my two ASP Taclites. I used a different strecthing technique: I just carefully dry-stretched them (with flashlight in), sustained the stretch approx. 30 seconds and repeated this a couple of times the first day, and once or twice the second day. That's all that was needed
The ARCAAA fits perfectly in that little battery pocket, which makes me wish for a second battery pocket on the other side.
I'm surprised that Surefire and Streamlight haven't come out with something similar.
Nice website!
Best regards,
Brightnorm