Climbers have haul bags, commuters have the Critical Mass® bag. This take-it-with-you bike bag carries enough gear for a full day; from a presentation at the office to an evening bouldering session. It has padding on the back and along the contoured base to protect its contents and provide structure. A removable padded computer sleeve suspends a 17-inch or smaller laptop off the ground to protect from hard knocks, and can be paired with the detachable waist strap to create an independent laptop sling. The cover flap overlaps the sides of the bag to keep out rain; its pocket closes with a water-resistant zipper. Internal pockets hold small items securely; there's even a place for pens and pencils. An external side pocket holds a cell phone, keys and your power cords. With an adjustable shoulder strap, stowable waist strap, topside carrying handle and a reflective strip for better visibility in low light. Made of a 600-denier 100% recycled polyester with a polyurethane coating and a Deluge® DWR (durable water repellent) finish.