I have two of these. They're reusable shopping bags that roll up into a built-in pouch. But with the sort of design and quality you'd probably expect from Peak Design. They could definitely fold/scrunch up smaller, but that would make it take longer to do. I've had a similar bag that was much smaller to carry, but it took at least a couple of minutes to pack it away - these can be done in maybe ten seconds. They're strong. The handle is comfortable. They have a zip, so your shopping doesn't get wet if it's raining. I live in Devon, it's probably raining. I almost always have one in my bag ([[Wandrd Rogue 6l Sling]]), and if I *don't* have one, it's most likely because I have two. I may yet get a third one, as I way too often seem to get *just* too much shopping to fit in two bags.