From PM's website:
The goal is to take apart and reassemble the parts of the cross. Not to be confused with the Aluminum Cross that is also designed by Wil Strijbos (and looks very similar) - the internal workings of the Sweta Cross are very different. This puzzle has four transparent "windows" which allow you to see very small ball bearings that are a part of its inner mechanism. Made to be a challenge for the more seasoned puzzler, this lovely puzzle also comes engraved with Wil's signature as well as the name of the puzzle. A wooden display stand (plate) is also included.