Britannia bullion contains 1 troy ounce of fine gold at a millesimal fineness of 999 (24 carat). Between 1997 and 2012 silver bullion coins have also been produced under the name "Britannias". The alloy used was Britannia silver (millesimal fineness 958). The silver coins were available in 1 troy ounce (31.1 g), ounce, ounce and ounce sizes. Since 2013 the alloy used is silver at a (millesimal fineness 999). In 2016 the Royal Mint launched a series of 10 Queen's Beasts bullion coins, one for each beast available in both gold and silver. The Royal Mint also issues silver, gold and platinum proof sets of the circulating coins, as well as gift products such as gold coins set into jewellery. Non-UK coinage Outside the United Kingdom, the British Crown Dependencies of Jersey and Guernsey use the pound sterling as their currencies. However, they produce local issues of coinage in the same denominations and specifications, but with different designs. These circulate freely alongside UK coinage and English, Northern Irish, and Scottish banknotes within these territories, but must be converted in order to be used in the UK. The island of Alderney also produces occasional commemorative coins. (See coins of the Jersey pound, coins of the Guernsey pound, and Alderney pound for details.). The Isle of Man is a unique case among the Crown Dependencies, issuing its own currency, the Manx pound. While the Isle of Man recognises the Pound Sterling as a secondary currency, coins of the Manx pound are not legal tender in the UK. The pound sterling is also the official currency of the British overseas territories of South Georgia and the South Sandwich Islands, British Antarctic Territory and Tristan da Cunha. South Georgia and the South Sandwich Islands produces occasional special collectors' sets of coins. In 2008, British Antarctic Territory issued a £2 coin commemorating the centenary of Britain's claim to the region. The currencies of the British overseas territories of Gibraltar, the Falkland Islands and Saint Helena/Ascension — namely the Gibraltar pound, Falkland Islands pound and Saint Helena pound — are pegged one-to-one to the pound sterling but are technically separate currencies. These territories issue their own coinage, again with the same denominations and specifications as the UK coinage but with local designs, as coins of the Gibraltar pound, coins of the Falkland Islands pound and coins of the Saint Helena pound. The other British overseas territories