Roarmaster,

Those are good flasks, and still to be found in the states. I always thought the blue hard slip cover was for when packing it externally on a backpack and it was crushed into a hip bottle pocket you could just lift the bottle out, the slip acting as a holster. Didn't think about UV.

I used that for trail hooch but then gave it to my kids. Wasn't big enough for the drinking we do out there. hmmm.

I also like that there is a 1oz plastic shot glass fitted to the cap. It's very sturdy, never once thought it would pop off.