This is a stand and drawer for the 24" M1 iMac, released in 2021. It's 41mm tall, and fits perfectly under the iMac's base.
There's a half circle cutout in the back of the stand, and holes in both ends of the drawer. Since the footprint of this iMac is pretty small, the drawer isn't huge either - not quite long enough to fit a 3x5 card. I probably will use mine without the drawer, unless I find a bunch of tiny things that I need on hand. But if you need to plug something in either with or without the drawer, you're covered!
I didn't need supports on mine (just for the holes in the drawer), though I see some similar designs do suggest you use supports. Something to watch out for!
The author remixed this model. Imported from Thingiverse.
Remixed for the 2021 iMac