Effect :
 
Magician removes a deck of cards from its case and separates out the King of Hearts, King of Clubs, Queen of Hearts & Queen of Clubs. He returns the rest of the deck into the case and places it on the table in full view of the audience.
 
He now holds these four cards in a fan in the order King of Hearts, King of Clubs, Queen of Clubs and Queen of Hearts. He shows both faces of these four cards. He pairs the two Kings and places them face down on one side of the table and pairs the two queens and places them on the other side. He casts his magic spell and shows that the card have magically changed places and have become matched pairs of King of Hearts with Queen of Hearts and King of Clubs with Queen of Clubs.
 
He now gives these four cards to a spectator to hold saying, no matter where in the deck these cards will be placed & mixed, the magician can bring them out in a second. He takes the same pack of cards from the table, but as he takes out the cards from the case, they are seen to have shrunk to a deck much smaller in size than before. The mini deck is handed over to the spectators and he sees that all the cards have shrunk leaving the four cards that you are holding. The spectator obviously can not mix the four cards as they are too big to mix in the mini deck and he, along with the audience, is not only amazed but also amused. And even if he does mix the cards the magician can pull them out in a second!
 
This is one of the classic unbranded Made in India versions of the effect. With a bit of time and a matching mini deck, it can easily be updated or customized to a different style of cards to suit your performance or display preference.