Pack Trail Blitz 12L. Black Diamond Trail Blitz 12L is the perfect backpack for your adventure.. Whether you’re bagging the Grand Teton in a quick car-to-car push, heading into the mountains for a scramble up your favorite ridge, or simply looking for a no-frills day pack for a few days of travel, the Trail Blitz carries everything you need while remaining light and fast. Featuring the signature Blitz-style main opening for quick and easy access to your gear, this pack also comes with two integrated Z-Pole sleeves, so you can stash your trekking poles when the trail ends and the climbing begins. The BDFlash pocket is specifically designed for headlamp storage for those pre-dawn or after-dark missions, and an internal security pocket keeps your keys and wallet safely stowed away. Four connection loops along the back allow you to mate the Trail Blitz to another larger pack so you can have a quick-detachable summit pack on bigger missions. And to top it off, the entire pack turns inside-out and is stored in its own pocket.