"New Outlander bags are awesome, and they very durable. I've been using mine for two years, and it shows very few signs of wear. I like to hike down to the lake and read, and I can take two water bottles, a small lunchbox, sunscreen, bug spray, first-aid supplies, a book, a cooling towel, and my phone." —grovemenglish, from this roundup of things we tried
"I got the large size to use as a diaper bag and it holds a crapload of stuff. The material is thin, but construction feels sturdy. I can fit in his portable changing kit (mat, 3-5 diapers, wipes and diaper sacks), hand sanitizer, wallet, keys, travel pack of Clorox wipes, tissues, pen, mirror, charger, headphones, power bank and two jackets. I've also used it as a weekend bag and managed to fit in three outfits, a set of PJs, huge toiletry bag, sports towel and a small ziplock bag of make up. I've had it for a while now and the only signs of wear are on the two side mesh pockets". —reikoko, from the same roundup
Get one from Amazon for $17.32+ (available in 11 colors and another size/style).