The Session 8L bike hydration pack is a minimalist, yet full-featured pack combining the cooling comfort of a breathable back panel with airy shoulder straps. This narrow, lightweight pack features a 2-liter vertical hydration reservoir with a bite valve. The pack offers plenty of storage including an organized front pocket, a fleece-lined sunglass pocket, additional side pockets plus external attachment straps. The Session is a do-it-all bike pack to keep you out all day on the trails. Details: 2L/70oz Hydrapak reservoir, phaser bite valve, breathable air flow backpanel and shoulder straps, external attachment straps, fleece lined sunglass pocket, internal organizer pockets, safety light attachment, integrated rescue whistle-sternum strap, limited lifetime warranty. 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. Dimensions: 488 cubic inches (8 liters), 17'' x 7'' x 3'' (43 x 18 x 7cm). Material: Nylon, Polyester.