This is the famous Pyraminx puzzle that has been around for 40 years, and still it captures the original fascination.
Pyraminx is a triangular pyramid-shaped (or tetrahedron) puzzle. The parts arranged in a pyramidal pattern on each side of the puzzle. The layers can be rotated with respect to each vertex, and the individual tips can be rotated as well. It was designed by Uwe Meffert in the early 1970s.
Mix up and put back to the start.