It is a holder for Ugmonk Analog index cards, but for Gridfinity.
This is inspired by the Ugmonk Analog. The battery holes are 5x1 mm, the same that you can find in the Gizeh cigarete papers. The size of the battery holes is parametric though.
The holder is used for the daily todo list. You can buy the Ugmog Analog cards or just use regular medium sized index cards. I actually printed my own with a 7mm corner radius. (Sorry Ugmonk, but shipping and tax to Europe is out of proportion!)
This is my first Fusion 360 project, so please give me constructive feedback!