This puzzle is made out of Trispan which is a metal material.  The shell is made out of a polycarbonate. 
You will need to figure out the best way to move the rods so that they can be removed from this puzzle.  Just keep trying and you will get it.
Due to this being a handmade puzzle, there may be imperfections.  The solution of the puzzle is still the same.

• See at Puzzle Master