Jon Allen is one of the cleverest close-up performers around. With Jon's new Double Back, the audience will be so dumbfounded you will have to remind them to breathe! Double Back is quite possibly the most powerful transposition effect you will ever perform. Four cards (two 5s and two kings) are openly shown. The two 5s are placed on someone's hand and you cleanly show you are holding the two kings. Instantly, you are now holding the two 5s and they are holding the two kings. Simple. Direct. Powerful. When Double Back was first released, it became one of the most acclaimed packet effects ever. Now, with this updated release, you will see the routine performed in a working environment. You will also learn handling advice, presentations and subtleties perfected through thousands of performances. It has never been easier to perform an effect with such a strong impact! For years, Jon Allen has begun close-up set with Double Back. Why? It gets people involved. It's easy to understand. No cards are picked. It's extremely magical. It seems too impossible to be done live. It resets instantly. It quickly tells the audience, "This guy is good!"