I ordered both the 20L and the 26L bag in order to actually see the difference since the Kailas listing shows the same photo for both the 20 and the 26.There are some fairly significant differences, that you may be able to notice from the photos I’ve included. (See yard stick and beer can for size comparisons)1. The waist strap on the 26L has pockets built in on both sides. The 20L has none.2. The 20L has ONE main pocket with a single very small front pocket (about the size for sunglasses and small items.The 26L has TWO HUGE pockets; one against the back that holds a bladder and it shaped for the lumbar backing, then an additional pocket the entire length of the bag. Lots of room!As well as having a small pocket for things like sunglasses.3. The front open stretch storage is larger on the 26L and the locking clip stores protected under the logo. On the 20L the clip is exposed (minor detail).Both bags are very comfy (having not hiked with them yet, just tested around the house. The shoulder straps are insulated.One thing to note, as these are technically small DayPacks, the length between the shoulders and the waist strap need some dialing in, or the waist strap will come up very high on you.So far, from just an in-home try-on, these things really stack up to the competition, and I doubt there is much out there with these materials and features at this price point.
