This is a funnel designed to fit the standard 55mm x 100mm tipping bucket rain gauge used in many commercial and DIY weather stations.
This gives a resolution of around 0.059mm of rain compared to the ~0.35mm with the basic body.
It is designed to simply be a tight fit in the original body and needs no screws or glue.

Creality

Ender-3 v2

No

Yes

0.28

25%

I used a 0.8mm nozzle to reduce print time to around 10 hours.
Use TREE support with the funnel circular opening downwards on the slicer.
The attached gcode worked well on my Ender 3 V2