Bi-metallic coin dated 2006 (minted at Noida). Since 1996, Canada has also produced bi-metallic $2 coins (nicknamed "toonies"). Great Britain has issued a bi-metallic 2-pound coin since 1997; and Singapore has issued a bi-metallic 1-dollar coin since 2013. The first ever tri-metallic circulating coins were 20-francs coins introduced in France and Monaco in 1992. These were similar to the corresponding bi-metallic 10-francs coins, but had two rings instead of one. As well as circulating coins, where they are generally restricted to high-denomination coins, bi-metallic coins are often used in commemorative issues, often made of precious metals. For example, the only bi-metallic coin
Loonie and its 11-sidedness matched that of the already-circulating Susan B. Anthony dollar in the United States, and its thickness of 1.95 mm was a close match to the latter's 2.0 mm. Its gold colour differed from the silver-coloured Anthony dollar; however, the succeeding Sacagawea and Presidential dollars matched the loonie's overall hue. Other coins using a curve of constant width include the 7-sided British twenty pence and fifty pence coins (the latter of which has similar size and value to the loonie, but is silver in colour). After its introduction, the coin became the symbol of the Canadian dollar: media