Trick Effect & Routine:
This is an idea from the product Vox Box. This is the same concept but a different handling and setup making this original, I hope.

Effect:
After you do some card effects you borrow a ring. The performer suddenly disappears the ring. He directs the attention to the card case that was sitting on the table the whole time. He picks up the box and gives it a shake and you can hear a rattle, open the box and the rings falls out of the box onto the performers hand.

Preparation:
An empty card case and a US Dime. Or you can get a washer about the size of a dime.

Method:
Xov Box- Put the dime in the case but pinch near the bottom flaps on the long sides. The opening of the case will begin to form an oval. The dime will then lay on the bottom of the case. It must lay flat. Release the pinch and the front and back of the case will pinch the coin in place. To make the rattle, pinch the long sides together and give it a shake. To stop the rattle, pinch the long sides and have the coin lay flat on the bottom of the case then release the pinch. That is the mechanics of my Xov Box.

Now borrow a ring and disappear it. Nothing simple than a false transfer and retain in finger palm in the right hand. Next direct the attention to the box. Give it a rattle then lodge the coin. Next you flip open the flap, pretend to dump the ring out of the box and onto your palm but you really mimic it and display the ring in your palm. Think shuttle pass.

Comments:
That is a brief example on what you can do.

Also if you want to display the case empty you can palm the dime first. Then when you ask to borrow the ring, you load the coin in the box.