skateboarding daypack with patented rib cage constructionâ„¢. the db skateboarding daypack offers enough space for all the essentials you need in the skatepark. strap your board comfortably to the backpack with the fully adjustable straps. you'll also enjoy an external water bottle holder and a supportive back panel. rib cage constructionâ„¢inspired by the human rib cage, which protects the body's most valuable organs, db's patented rib cage constructionâ„¢ protects your gear in the bag. the rib cage construction is built from strong, lightweight abs ribs formed as a triple-fold structure. this means that conventional padding can be dispensed with. this makes the bag lighter and yet protected all around.