Maxello Magic

The performer hands an envelope to a spectator to look after. He spreads cards face up, showing that they are shuffled, squares them up and turns them face down. These cards are unique, they have been numbered from 1 to 52. Spectator thinks of a number between 1 and 52, then names it aloud. A card is located according to the number given by the spectator. Finally envelope is opened, an exact replica of the card located by the number is found!