You get four red-backed cards, custom printed with red Bicycle back design, in classic gag card motifs: the 14 of spades, the 15 of diamonds, the venerable three-and-a-half of spades, and a very fancy Tree of Hearts.

(Note:  these cards are NOT printed by the US Playing Card Company.  They are imported, and while they handle well and smoothly, they have a slightly different finish from cards produced by USPCC.  Also these cards are a tiny bit longer than standard Poker-sized cards.  When in a standard deck, they protrude about 1/16 of an inch.  So best to use them separate from the deck, in a prediction envelope of card box.  Or in the deck, they can always be easily located and cut to.)

We magicians think these are just silly gags, but if played well, the revelation of the 14 of spades, or the three-and-a-half of clubs, or even the Tree of Hearts, not only amuses the lay audience, but can profoundly knock their socks off, too!

The effect as I usually do it: Spectator picks a card ("freely" selecting the 7 of spades). You explain that your facedown prediction card cannot, of course, be the same card, but it will be exactly double his card. You give examples, "if you picked the 2 of Hearts, my prediction would be the 4 of Hearts, etc". After the byplay when he names the 14 of spades, you show the correct prediction! Another great use is for a blendo card effect: two cards selected (again "freely", the 10 of diamonds and the 5 of diamonds). Via some sleight of hand, a card box, or maybe some other switch, you change the two selected cards into one card that equals their combined values -- the 15 of diamonds!

These little decks of cards are great for stimulating your imagination. 

Use them as predictions in unexpected places -- one stuck to the bottom of a small hour glass, for when time runs out to find the selected card.        Stick one on the back of your business card,  for a memorable revelation of a selected card that will make them remember you.

Or force a low card like a Two, and then "find" the wrong card -- a Ten. "Oh, your card was smaller than a Ten?" Then pull out a tiny Two that matches the selection. 

Or glue the whole deck onto a jumbo card for the 52 on 1 effect, but have one mini card missing -- the one that matches the selection...    

You get the idea.   No instructions included, but if you know some basic card magic, you can find tons of ways to use these fun little cards.    (A few of the mini cards are shown in photo with a poker sized card, so you can tell how small they really are!).