This out of stock hard to find is a Disney Gravity Falls Mabel & Dipper Fist Bump Mini Backpack BoxLunch Exclusive.  Featuring a print of Dipper and Mabel fist bumping on the front zipper pocket, this bag also includes portraits of Waddles and gnome on the side pockets.  With a metal Bill Cipher badge and adjustable straps, this backpack is the perfect accessory for uncovering mysteries.  

Polyurethane, polyester lining.  8 1/2" W x 10 1/2" H x 5" D

The bag is new without tags.  Please see photos for more details.