Hydrapak Seeker - Collapsible Water Storage (2L, 3L, or 4L) - BPA & PVC Free Camping Hydration Reservoir
Rugged, lightweight, and versatile are some of the reasons why the Seeker hydration storage system is so great. It's completely collapsible, and comes inside a handy stuff sack. Once you fill it up with water, you can attach it to your pack using the lashing tabs built-in right on the Seeker. Feel free to freeze it on sweltering summer days or fill it up with hot water for winter days spent out in the ice and snow.