What a really charming effect this is from Vienna Magic from an original idea from Wolfgang Grosskopf. I used to have a different version, but this one looks a lot nicer. The props do all the work for you, but you are able to switch the Magician (Jack) in the crate for the Assistant (Queen) in the sack. Even though you can clearly see them right to the very end. The transposition is instant and easy to do!