Good deal - CamelBak Tactical Hydrobak Hydration Pack 60282 (NSN: 8465015417956)

I bought three of these for my kids on a summer hike and it allowed them to climb without restriction. 50oz was enough for a child but this capacity may need to be refilled for an adult. They worked great and recommend their use.
Pros: Small and durable
Cons: 50oz capacity

This review was written in the old system and had content requirements that are different than reviews written today.