It is a hexasphericon, or a hexagonal sphericon. It rolls oddly.
You are meant to print out two of the halves, and one middle connector. They join to make the hexasphericon.
Print the halves flat side down. Print the middle part's length side vertically (it is symmetrical so it doesn't matter which side, so long as it is standing on one of its hexagon side).
There is a pre-made 0.1mm tolerance between the middle connector and the halves. It is likely you would want to do some light sanding for the middle to fit nicely. You could gently tap it in with a wooden mallet. The object is held together by friction, as it is designed so you can disassemble it and change the shape of it.
*If you regularly disassemble and assemble it, you may find the fit gets less tight on its own.