Pennie wallet is super convenient and is super hard to beat. Details: Exterior credit card slots, zippered coin pocket with key clip, 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: 4'' x 3.5'' x .25'' (10 x 9 x 1cm). Material: Poly Straw Woven, Cotton Canvas.