A round box, which holds 4 coins. Set the box on the back of your hand. Lift the lid, and the audience can see the coins fill the box. Cover the box, tap it, and the coins instantly pass through the box and the back of your hand. Lift off the lid, and show the box is now completely empty.
This Boston Box is machined from hard wood in the size suitable for US 50 cent coins and comes with instructions for several effects.