FYI, Blackburns Hydrasak sucks. My camelbak was showing some wear, and I wanted a bag to hold my tools, so I bought one.

The valve is operated by a dificult to use push-button rather than a bite valve. it leaks, its a pain in the a$$ to use, and it eventualy fell completely apart on me awhile back.

I still like the bag for tools, tube, etc, so I just put my old camelbak bladder in it.