I walked in to the hiking store to look at larger backpacks. I tried them on and asked about foldable daypacks as I’d seen them online and they seemed like the perfect alternative to having a large and small backpack. I was walked over to a rack with these tiny little packs about 5cm x 3cm x 4cm and was told these are 2oL. I was instantly sold and bought one right away. It is super lightweight and can be packed in to itself when I don’t need it. I thought it would sit terribly on my back but it has been surprisingly comfortable and strong even with my computer (1.5kg), camera, phone, wallet, water bottle and even with a huge accounting book once.
The only negative is that with such a compact pack there are not pockets so everything ends up together in the bottom, which is also where sand ends up after the beach. Other than that it is perfect for me. I am interested to see how long it lasts for.