One of most popular styles from Dakine, the Session 12 combines the ventilated backpanel and organized front pocket with a lightweight, narrow profile and a 2L hydration reservoir. A great option for a simple pack with the perfect amount of features. If your bag gets dirty, Dakine recommend hand washing with mild soap (like Nikwax Tech Wash), cold water and a soft bristle brush. If hand washing is not going to do the trick, use a front loader washing machine. To ensure your backpack doesn't get tangled, place inside a pillowcase or mesh bag before washing. Always use cold water, mild soap and run on a gentle cycle. Never bleach your pack. Hang to dry in a warm but shady place, ensuring both inside and out are dry before storing. Details: 200D nylon, 600D polyester, phaser bite valve, breathable air flow backpanel and shoulder straps, full face or trail helmet carry, fleece lined sunglass pocket, internal organizer pockets, safety light attachment, integrated rescue whistle-sternum strap, limited lifetime warranty. Dimensions: 700 cubic inches (12 liters), 17'' x 8.5'' x 7'' (43 x 22 x 18cm). Material: Nylon, Polyester.