Curios Cross is a Put-Together or Interlocking puzzle made by manufacturer Magnif. 

Made of clear plastic, to better see the intersecting planes, your goal is to build a cross from only three pieces, two of them identical. The puzzle comes in its box unsolved so there's no way to cheat. Also, I think if it were already assembled, it could very easily be broken in the disassembling process, due to the nature of the plastic used. This way you have to think how to correctly place each piece to achieve the desired shape.

I'm not going to explain a step by step solution, but I can give you a few hints to better tackle the challenge. Given that you have three pieces to work with, and two of them are exactly the same, that leaves a single piece that's obviously the main one and the first of the sequence to build the cross. Next, you just have to find a correct  order to put the other two pieces, keeping in mind that only when the three pieces are partially connected, you can slide them into place.

Once you've successfully built your cross, it's awfully hard to disassemble it, but if you do it right after, it's easily accomplished, because you may still remember the order that the pieces were placed. You don't need to worry about that though, because once the cross is built, it's a beautiful decorating item for any desk, unless you want to challenge any of your friends.

Overall, the Curious Cross is a nice challenging puzzle. The fact that it's made of clear plastic with a bit of tint, makes it visually much more appealing, although it's very easy to break if you're not careful. 

There's an I.Q. rating level on the back of the package based on the time it took you to solve the puzzle:

10 Minutes - Genius

30 Minutes - Brilliant

60 Minutes - Above Average

Can you do it under 10 minutes? My time was approximately 45 minutes, so no Genius, unfortunately... 

You can check PuzzleMaster's website for more Magnif and other related puzzles.