My apartment complex couldn't provide an adequate replacement knob for my shower. Enter me... it has a 10.5mm x 10.5mm square peg hole on the underside. I am really pleased with the results.0.1mm Slicing 2 Shells 25% infill PLA (Totally fine in the shower don't let anyone tell you different) These setting were overkill, I was worried about the knob breaking under the torque it hasn't not by a long shot.