I have one of those bottles too, I piked it up s/h in perfect condition and put it in the bottom of my bag as a spare. When I got it it had no cover and had spare o-rings taped to the side (I'm guessing the other guy hadn't used a cover), I didn't bother with a cover, the first time it got used I lent it out (to a renowned idiot) and it came back at the end of the day scuffed to bu66ery, to the extebt where you could no longer read the text on the label! Guess what? Yep, I went and bought a cover for it!