The Marmot Ultra Kompressor 22 Litre Rucksack is a lightweight day pack that can easily be compressed to shrink the load down (hence the name), so there's no unwanted movement when the bag is partially full.
Marmot says:
Need a super-lightweight pack that doesn't skimp on storage and features? The Ultra Kompressor delivers with generous mesh stash pockets, comfortable molded shoulder straps and back panel, and three points of compression for shrinking any load down to size.
Marmot's Ultra Kompressor 22 Litre Rucksack is a lightweight day pack that can easily be compressed to shrink the load down (hence the name), so there's no unwanted movement when the bag is partially full. It's a really simple pack, there's not many features to over-complicate it and it's built to last with really solid construction & ripstop fabric on the base.
It's important to note that the Ultra Kompressor pack does not have a removable frame sheet like the Kompressor and the kompressor Plus packs - even though it is stated on the tag and on Marmot's website that it does. Instead it has a fixed molded, padded pack with inserts for air to pass through.