Ecoo via Amazon offers the Ecoopro 20-Litre Durable Lightweight Packable Travel Hiking Backpack Daypack in Blue or Green for $15.99. Coupon code 9LFNLGL5 drops it to $10.87. Plus, Prime members bag free shipping. (Non-members can spend $35 to bag free shipping; otherwise, it adds $5.58.) That's $19 off list and the lowest price we could find. It measures about 16" x 12" x 7" and features rip and water-resistant nylon and stuffs into its own pocket for storage.

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