The POC VPD 2. 0 Spine Pack 25 gives you everything you'll need for any mountain biking adventure. This pack comes complete with VPD 2. 0 back protection for those moments when things go shell side down, hydration compatibility to keep you going on hot days, and tons of pockets and storage to hold your phone, mid ride candy corn snacks, and any other ride necessities. POC's VPD armor has all the comfy qualities of soft and flexible armor with the strength of hard shell. It's soft and flexible to move with you as you ride, and hardens instantly in the event of an impact for consistent protection across multiple hits.