Check the listing for details. General Services Administration (GSA) Challenge Coin with velvet case. Condition: New. Listed at 19.99 USD. General Services Administration (GSA) Challenge Coin with velvet case. This is a great looking General Services Administration (GSA) challenge coin. Coin has reeded edges and is about 1 9/16" in diameter. All details are raised lettering. Coin is contained in an acrylic snap tight holder and displayed in an attractive black velvet presentation box which makes this a very impressive gift. The General Services Administration, an independent agency of the United States government, was established in 1949 to help manage and support the basic functioning of federal agencies. GSA supplies products and communications for U.S. government offices, provides transportation and office space to federal employees, and develops government-wide cost-minimizing policies and other management tasks.