Based in Sarasota, Florida, NGC or Numismatic Guaranty Corporation, is the world's largest third-party coin-grading corporation. With over 38 million coins graded since the company was established in 1987, NGC offers a unique service for collectors. The company employs over 30 full-time graders who are barred from trading in coins to ensure complete impartiality. Grading is professional and consistent and coins are backed by the industry recognised NGC guarantee and returned in the company's advanced protective holder. The firm undertakes various types of grading of coins, medals and tokens and there is a membership option.