Patent attributes
A bag or a rucksack has a base part having an enlargeable packing volume and first and second connection elements, between which a flexible wall element is arranged. A first packing volume is formed when the first and second connection elements are connected and the wall element is arranged in the first packing volume at least in part, and an expanded packing volume is formed when the first and second connection elements are separated. An additional part is provided which has an additional packing volume, and a first additional connection element is provided on the wall element and a second additional connection element is provided on the additional part. The additional part can be fastened to the base part by means of the additional connection elements.