Staples PACK N FOLD 50708 Foldable Lightweight Water-Resistant Backpack, Black Shop Early

This bag is only small till you open it.
Foldable and portable, you can fold it up into a notebook size small pocket and toss it in your handbag.
This handy bag is ultra lightweight when empty and helps you avoid extra weight when full.
This lightweight foldable backpack features 2 side pockets and 1 front zipper pocket for easy access, and adjustable straps.
Featuring wide breathable mesh shoulder straps, it offers comfort and promotes a healthy back.
Two zippered compartments. Main pocket is Large enough to carry what you need. Outer smaller pocket is great for quick access.
Inner pocket is perfect place for valuables. Two side mesh pockets for water bottles.