I built the models for printing on the Prusa Core One+.  The models are all .1mm larger than actual size to help with shrinkage issues.  Originals were printed in PLA with .4 HF nozzle at .2 balanced setting, gyroid infill at 15 %. To use, insert thumb from underneath, thumb nail facing sideways and turn 90 degrees for fit.  Fit should be snug and comfortable.  Multiple sizes available.