A replacement knob for a washing machine / dishwasher / etc inlet.Just print! There is a bit of an overhang that i missed, but its only small and printed without issues - just clean the hole out with an alan key or screwdriver. This fitted fine for me, if a little tight. I printed 100% infill in ABS (really didn't want it snapping if any leaks appeared!). I've only used this print for the cold water valve. i'm unsure how long it would last on a hot water valve, especially in PLA.