surprise! its a water bottle! gets the job done, and thats about it. good bottle, sturdy like all nalgenes.

get this if you don't want a hard plastic nalgene. i prefer it over hard plastic, nothing else really to say...

echoing previous reviews - good midlayer, not good stand alone. purchase for added insulation. took it on a month long mountaineering trip and it served me well on travel days where it was too cold for just a shirt, but not quite at a level for a insulated puffy jacket. if the wind hits big time, or if you sit down for a rest, throw on a wind layer. you'll need it

really light fleece, acts accordingly for wind - doesn't have any stopping power, but that's not why you're buying this fleece.

good for a layer over a base when it's not cold enough for a 300 weight, but too chilly for just a t-shirt.

haven't taken it out on any trips yet, but will. feels like the fleece around the zipper part at the bottom is wearing thin already. THREE STARS!

if you aren't already familiar with these bottles, it's just an all around rugged water bottle. Use it for anything.

I like this material over the regular hard plastic, have a bit of a squish to them, not so rigid. So if you like this characteristic, pick one of these up over the regular. I also have a 16 oz of the same material which I like. It has a narrow mouth which is easier on drinking, but harder to clean and fill. Wide mouth = easier to clean and fill, less easy to not spill on yourself if you're a little over-enthused about liquid intake at the time.