The OEX Drysac is an uber-lightweight way to ensure your gear remains un-soggy in tough conditions. No one wants their spare clothing to get wet and the waterproof, abrasion-resistant fabric (with fully taped seams) will sit like a cacoon of dryness around your stuff, even in the pouring rain. This larger 40 litre bag is ideal for stashing your change of clothes or larger essentials - essentially making your entire backpack a dryzone.