There have been three sets of coins in Ireland since independence. In all three, the coin showed a Celtic harp on the obverse. The pre-decimal coins of the Irish punt had realistic animals on the reverse; the decimal coins retained some of these but featured ornamental birds on the lower denominations; and the euro coins used the common design of the euro currencies. The pre-decimal and original decimal coins were of the same dimensions as the same denomination British coins, as the Irish punt was in currency union with the British pound sterling. British coins were widely accepted in Ireland, and conversely to a lesser extent. In 1979 Ireland joined the Exchange Rate Mechanism and the Irish punt left parity with sterling; coin designs introduced after this differed between the two countries.