Sea To Summit U-sil Nano Daypack 18L

Really small and light, and really handy and functional despite its small size. The only downside is that you can't get shoulder straps, but that was taken care of with a couple of knots.

A backpack that packs down really small. Of course, the straps weigh thin if the backpack is full, but it's not even reasonable to ask for anything else. Good buy!

5 cm narrower for the starting of the carrying straps so it would stay better on the shoulders, otherwise the idea / purpose works.

Very slippery material. Stayed in place on the back when I put the chest strap on. The thin shoulder straps are heavy if you carry heavier things. Suitable for very light carrying.

Really small package and also fits well back into the small storage bag. Seems convenient. You have to take it with you in your daily bag.