2008 Two Coin International Year of Planet Earth Proof Coin set, The set complements the Six Coin Proof Set and features the standard One Dollar coin circulating design and the special Twenty Cent coin design, Weight: $1: 9.00 gr, 20c: 11.3 gr, Diameter: $1: 25.0 mm, 20c: 28.52 mm Please contact Adelaide Exchange Jewellers to find out more on this item.