Introducing the P.F.V. - Phone. Flask. Vest. 
This pack is one of the most fun packs we've designed. The fit is awesome for mountain biking, running, and obstacle course racing. It's designed to hold the essentials and not much more. As you can see from the pics, we minimized the amount of material on your body to achieve maximum breathability. The soft flask holder up front is great for 450ml and 600ml soft flasks (it comes with a 450ml). Then the pocket on the outside of it holds your smart phone wonderfully. On the right side is a shoulder pocket for electrolytes and backup nutrition. On the left side is a dust cover for the bite valve (our OCR people will dig that!). The back has shock cord to hold a jacket, and a small pocket perfect for small bags and sticks of nutrition. 
Sizing: Less than a 40" chest diameter, size S/M. 41" to 54" size L/XL.
Pack weight without flask: 7.3 oz.
Patent Pending / Made in Vietnam