I have a grey riot backpack, complete with logos, a few drawings and a "enter your summoner name" area, it was purchased around 5 o 6 years ago, and would love to know the model name or learn more about it.
This is a backpack that was given out to all new Rioters until a couple of years ago as part of their onboarding. I still have mine from 2016 :)
EDIT: I realize this is like trying to control the weather, but these - like most company merchandise - aren't really meant to be sold. I'd appreciate it if you didn't try to sell it on.