I have two different types of inserts for my bottles and as I don?t know which one Campmor sell I will tell you about both of them.

Splashguard was the first one I saw to come on the market and it works pretty well all thing considered.

The insert made by the Nalgene company unmodified in my opinion is not as good but modified I think is better than the Splashguard one.
This simple modification is to drill a ? inch hole at the 12 o?clock position to let air into the bottle.

My lexan bottles and inserts get used almost daily and are kept clean by a trip through the dishwasher which makes it very easy unlike the camelback type of hydration equipment.
An insulated bottle cover keeps things cool in the summer and keeps them from freezing in the winter.

All and all the Nalgene lexan bottles are a durable and low maintenance way to carry hot or cold beverages for your drinking pleasure.

Oh and lest I forget on a really cold night just pour one full of boiling water stuff it in an old wool sock and it will keep your feet warm all night long. <img src="/images/graemlins/grin.gif" alt="" />