Looks like the description was truncated. After stating the purple bag is made of 600D polyester, it adds the information for the black quilted bag with a “:” and no details about the fabric.
I think this is the Amazon listing, if that helps: https://www.amazon.com/AmazonBasics-Amazon161214-Underseat-Luggage-Black/dp/B071G2D5MM
Reviews are helpful, but I didn’t see any details about the fabric in the Amazon listing. It has good reviews but I am skeptical about the need for wheels and a telescoping handle on a relatively small bag. If you’re traveling with only an under seat bag, you could get some more useful packing space without them. If you have a checked bag, a bag this size should stack on top nicely.
We don’t have this bag, but we have 4 just like it from a different manufacturer and we love them. My teen daughters almost exclusively use this size bag when traveling and they do use the wheels. They pack a lot in a small space, especially with rolling their clothes and packing cubes.
We got them for a trip to Hawaii where Alaskan Airlines charged extra for checked bags, but we could each bring a backpack and a bag to go under the seat. For a family of 4 and a 2-week vacation, we checked two suitcases, took 4 of these bags and 4 backpacks and we took everything we would need including two mono-fins (the girls think they are mermaids) and their scuba equipment. We could have lived without the wheels if we had to, but why? We love this sized bag!
Thanks for the info. Are yours like the 600D polyester or the quilted version?