For sale is my Mountainsmith Zerk 40 Frameless Backpack. I used this pack for about half of the Pacific Crest Trail, approx. 1,000 miles. I really like the design of the pack. It has big bottle pockets on either side, and mesh pockets on the outside of the bottle pockets for snack and trash storage. the big outside mesh pocket it great for holding anything you need, and the double pockets on each chest straps are great for all the readily accessible things you may need throughout the day. I like the running vest straps as they distribute the weight across your chest very well and take the weight off of your shoulders. I cut off a few straps that I didn't use to save weight and streamline functionality. 

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