This is a simple device to securely hold a Gold or Silver coin while performing a "Ping" test. This will hold up to a 1/2-inch thick coin or bar. The Ping test is an audible method to help determine if a Gold or Silver coin is authentic. An authentic coin will have a distinctive ring when it is held in this tool and gently tapped. To use, simply squeeze the clip open, place the center of the coin in the center of the soft, rubber pads, and release the clip to secure the coin. Then use a wooden pencil, or similar object to gently tap the edge of the coin. An authentic coin will have a solid, consistent ring. Composite coins will have a harsh or duller tone. This tool can be used with any "Coin Ping" test app for your phone. This tool is based off an old clothesline pin used in the past to perform the ping test, updated with modern materials. This ping test tool is made of plastic, with rubber pads to prevent coin damage. The tool is 5" x 1-5/16" x 5/16". This sale is for the coin-holding tool only, you must supply a pencil or other "tapping" device. The coin pictured is NOT included. Many colors to choose from, custom colors may be available upon request, minimum 2 units. Pastel color variations are a limited edition, once the lot of 10 are gone, there will never be another exactly like them. Factory Second choice are fully functioning units. These units will have cosmetic blemishes, color variations, texture issues or other imperfections, but are fully operational. Sorry, no color choice as these are random units from production runs. Please feel free to ask any questions prior to purchase.