Effect - You pass a coin from your hand into a closed tic tac box in an INSTANT! Then you take a SECOND tic tac box and again, in an INSTANT, the coin has magically traveled from the first box to the second!
Easy to do and extremely VISUAL!
Passing a coin through a solid object is great, but it usually stops there. With THR-U, you pass a coin through a solid object, and then make it pass from that solid object into another. Even more mystifying!