The Off Trax 40+10 Backpack offers 40L main capacity with 10L expandable storage for flexible packing. It features an ergonomic EVA foam back panel for even weight distribution and breathable mesh shoulder straps. The adjustable hip belt includes pockets for easy access. It also has large side pockets, a zippered bottom compartment, a daisy chain with a pole holder, a sternum strap with a safety whistle, and is hydration system-compatible with a laptop sleeve for up to 15 inches.