The Topeak Fuel Tank is an easily accessible top tube bag which can store all your riding essentials in a place that is easy to reach for. Engineered with 420 Denier Nylon straps with a PVC Sponge outer material for longevity and style. There is a cable port so you can charge your mounted smart phone while riding! There is a divided main compartment with two (one on the medium) inner mesh pockets to keep your tools and snacks organized. Available in multiple sizes. The medium has a .5 liter capacity and weighs 120g. The large has a .75 liter capacity and weighs 150g.