ThinkTank R U Thirsty Water Bottle Bag Can be used as a "catch all" bag Folds flat when not in use Can also be used for lenses Bungee cord top-access: The bags feature a completely open top which is the fastest way to insert or retrieve a lens or other items. The bungee cord closure system allows you to securely pull the top tight, preventing anything from falling out Seam-sealed raincover: Unique to Think Tank Photo, all of the rain covers are seam-sealed for protection, similar to outdoor clothing and jackets. This is necessary to prevent the water from leaking into the bag where the raincover is sewn together