Please note that measurements of the bag are external, and internal space is less due to seal and air channel.
The capacity of these bags makes them ideal for suitcases and family holidays as the bags are fairly capacious. They will fill up if used for skiwear or coats, etc but for normal summer holiday wear, you will pack quite a lot into a bag, meaning that one pack should enough to sort out several suitcases.
The real benefit of these, as we noted in our introduction to vacuum travel bags with valves, is that you can seal the bags up at home and reduce them using a vacuum cleaner and the turbo valve, and then when you are away, you can use the roll up function to remove the air by pushing it out of the air channel at the bottom. All the functionality is explained in full in the Instruction Booklet on the front of the pack.