The file 'Valve Stem Compression / Insertion Funnel 3D Printer Model' is (stl) file type, size is 28.2KB.
This funnel allows for the compression and insertion of a tubeless tire valve stem from the outside of the rim when used together with https://www.thingiverse.com/thing:6058004 for ramming in of the stem. Use lots of silicone lube inside the funnel.
Print with 4 walls for strength.
As noted in the comments; this will be easier if you first dip the stem in boiling soapy water to soften it.
3Funnel_Customizer_AP2020_v8.6.stl | 124.7KB |