Stick these on any smooth surface with a 40cm sucker you can brought off eBay.
Print with opening flat on print bed.
A spherical micro planter for... succulent, it's the size of tennis ball. Pot has a sucker holder on its back, when attached, it lies completely flush to the windows like it's floating.
There are 3 other remixed version. A very special sinc(patrick) version, I don't know who did the original nerdy cartoon, but it's awesome, let me know if you (its author) feel attribution is required.
The internal dimension is structured such that it's thicker at the top at 6mm (or bottom when in use), use at least 2mm top and bottom shell to ensure it finishes nicely, take a long time to print this, so 'pulls all the stops'
Printed with PLA (translucent) and pain-in-the-butt ABS (orange)