The Gear Vest Pro is designed to be small on your back, but big on storage for endurance events. We took the same tiny footprint of our Gear Vest, but added rear cargo like the Endurance Pack (but we actually made it a bit more roomy than the EP so you can really load this up!). Plus we added trekking pole attachment areas on the front and back in 8 locations.
 
This pack is fantastic for running and riding short to super long distances. The 1L/35oz included bladder in the back has a typical range for most of 1 1/2 to 2 1/2 hours, but you can add soft flasks up front to increase your range. The oversized chest pockets hold plus sized phones, arm warmers, glasses and such wonderfully too, and the shoulder pockets are great for backup nutrition, sunglasses, gels, electrolytes and more.
 
The key to fit, cinch the sides first, not the front, until you feel the pack anchor on your shoulders. Then adjust the front harness as needed so you can breathe during movement.
 
Fits soft flask in 500ml and 600ml in the front chest pockets. 
 
Specs: Weight: 11.2oz, Bladder Size: 1L (35oz) included. Made: Vietnam. 
Sport Focus: Ride, Run, Explore. Cargo: 5L
Pocket config: Pocket 1 - 1L Bladder, Pocket 2 - Bulk Cargo, Pocket 3 - Zipper secured cargo and secure key clip.