The Mountainsmith Ultra Lumbar Pack is to an endurance trail runner what the high-tech equipment belt is to Batman. This lightweight pack comfortably holds two included 22-ounce water bottles, your MP3 player, and any other small trail essentials thanks to the four-point adjustment system and the AirFlow lumbar panel. There’s even a mesh quick-draw sleeve for your energy gels so you can get your goo on the go.
Bottom Line: All the tools you need for a long day on the trails.
This pack is incredibly stable when trail-running. If you need a pack that is very stable, breathes, holds two water bottles, has an mp3 player pouch and has a center pocket that's large enough for a wallet, keys, cell phone and a small medkit or food; then this is the pack for you. Great quality from Mountainsmith.
I got this pack off of SaC and I love it. However, the bottles are terrible. I'd been using a Nathan XTrainer Plus (horrible by comparison), but I fell in love with their bottles' valves and squeeziness. So, I recommend using Nathan bottles in this pack. A few notes on the design: 1) This pack has a fantastic frame-style suspension that keeps it off your skin. Genius. 2) The hip pads and the compression straps work together to make this really stable, which means you notice it much less than far lighter packs. 3) The front left mesh pocket works great as a Nathan 5oz nutrition flask holster. 4) A warning for guys: the red color scheme is more of a burgundy and looks a bit feminine.
I just got this pack and so far it's been great. It takes some getting used to if you've never run with a lumbar pack on before but it's really comfortable. I was looking for something that could hold two water bottles and my iphone and a few gels and this one does the job very well. Bouncing is minimal and it holds water bottles in a position that my arms were able to swing naturally (no chicken wings).Fit is good. Get this pack before they run out.