It’s the perfect little bag— just big enough to hold my wallet, keys, phone, sunglass essentials—that I then transfer from one big bag to the next. It’s an ironclad system, where I never lose anything important in the oh-so-risky bag switch. I originally
got it this summer from Muji before we went on vacation as a travel solution: I wanted to have a big carry-all, but I also needed to have a small bag inside. Bonus: It comes with a tiny pouch that’s just big for my digital camera; it also comes with a navy bag that fits inside it, which I used during our travels as our emergency medicine/elixir bag.
I couldn’t find the bag easily online, although if you live by a Muji, they have plenty of selection. I did find the same one on eBay.