I've tried some buttons to repair my kids' crocs, but something went wrong in all cases. This is a mod from one of the available options here but this one works ok. No need to use Horizontal expansion in Cura for the thing to plug properly. I only use PLA. If your temp is higher that 205 ºC the hole in the female part will tend to be smaller. That's the reason for the cut in the side. It will work always. Also the pin in the male side is conic. Of course, this model needs to be glued with CA.