Blue Paid Backpack 18" with Bonus Pencil Case Triple Pocket Plaid 18" Backpack with Bonus Pencil Case: 2 side pockets. Matching pencil case. Wipe clean with damp cloth. his Triple Pocket Black 18" Backpack includes padded, adjustable shoulder straps for a customized fit and increased comfort. It also features side mesh pockets for additional storage and three varied sized front pockets with zipper closures to accommodate your books, folders and other school supplies. This 100 percent polyester backpack includes an easy-to-grip top handle for convenience and an easy to maintain polyester lining.