2007-S US Mint Silver Proof Set. Complete Original US Mint packaging including Certificate of Authenticity. Contains 14 coins in stunning proof condition, displayed in three protective lenses. Each of these 2007-dated coins bears the “S” mint mark of the United States Mint at San Francisco. This “vintage” Proof Set has been previously owned. The 2007 United States Mint Silver Proof Set contains all 14 circulating coins in stunning proof condition displayed in three protective lenses. The half-dollar, quarters and dime are struck in 90% silver, generally referred to as coin silver. It is in “like new” condition and comes in its full original US Mint packaging, including the Certificate of Authenticity.