This is a very minimalistic insert for the "Return To"-boxes of the Arkham Horror LCG with flippable dividers. I decided to use thin walls and holes for the dividers insead of making thick walls with slits. The dividers are flexible enough to be bent for insertion. This design saves a lot of filament and makes the insert lighter.
For the Return To: The Night of the Zelot campaign, you will need one box and 22 dividers (or 23 dividers if you want to have one in the back too). I printed the fantastic Arkhamesque dividers (https://boardgamegeek.com/filepage/143554/arkhamesque-horizontal-dividers) scaled to 64% and glued them onto the dividers.
The author hasn't provided the model origin yet.