Available from http://www.world-of-magic.co.uk
You received a device to put in your arm. The device has two half dollar coins inside so if you move your arm these coins will make noise. Besides the device has a brass ring that you can adjust to eliminate the coin noise. If you put the device in your arm as picture show you can close the brass ring pushing your arm against your body. Imagine thousand routines where the people will believe that you have coins in your hands.