For one tree you need 4 pieces of "Guard-body" STL and 4 pieces of "Gasket" STL.
The gasket needs to be printed from a flexible filament such as TPU.
Instead of a gasket you can put a layer of silicone in the groove.

It is designed for 10 cm. diameter tree. If you need for 11 cm. diameter tree - print the parts on 110% scale. If you need a 12cm tree - at 120% and so on.

The model does not need print supports.

P.S. A sponge should be inserted between the tree and the guard.
Assemble it with bolts and nuts that fit the size you printed it.
Elastics are tied at the bottom so that the tree can grow.
When everything is assembled and installed, fill with water and you're done.
Don't forget to add water periodically. :)

Creality

Ender 3 Pro

No

No

0.1-0.3

15-20%

The model does not need print supports.