Pistol Grip shifter handle. Designed with 12mmx1.5 threads but I made it a little undersized to be able to run a tap through instead. Ill be more than glad to change the hole size for any tap.

Printing:

Works best with 100% infill IMO. But anything from 40-100 will work. .4 nozzle standard quality Print with no supports and standing straight up

The pictures is it threaded on a stock VW shifter.