Large capacity top tube bag with easy-to-use velcro mounting system. Convenient top tube mount keeps contents close at hand. Perfect for storing mobile phone, energy bars, wallet or tools.1800 Denier Nylon/PVC SpongeNylon StrapsMedium : One main compartment with one inner mesh pocketLarge : Divided main compartment and two inner mesh pockets.Cable access hole for charging devices with mobile power packMedium: 17.5x7.5x11cm, 0.5L, 120gLarge: 24x7.5x11cm, 0.5L, 120g