The 1966 sets were the first annual proof and uncirculated coins struck and released by the Royal Australian Mint (RAM). The six coin set consists of the bronze 1¢ and 2¢ cupro-nickel 5¢ 10¢ 20¢ and silver 50¢. The proof set is housed unsealed in a blue hinged-lid presentation case.

Because the coins in the set were not sealed storage in other than optimum conditions has resulted in a significant proportion of 1966 proof sets containing toned coins,spotting  particularly the bronze 1¢ and 2¢ pieces and the round silver 50¢ coin I have called them second quality.