Twin rings (body part swap)

"These rings were made of a rare metal, and are said to make the users feel as if they share everything with each other" the tagline on the product page says, you almost hear the corny accouncer voice now.

You think there is no way they are anything more then friendship rings and purchace them at least you can give them away or try them out, although you still aren't sure on the use.

You order them and suddenly you hear the door bell and rush to the door to anwser. You find a single box and nothing else. Its addressed to you with no return adress and when you get back upstairs and open it you find to ring boxes inside are the two ornate rings inside are exactly like the picture on the site. There is a instruction book with four pictures on it one shows two people putting on the rings, and then they swap a apple back and forth in there hands after thinking about it with little thought bubbles.

Still not fully understanding you decide you can at least give it to someone quick and try it out