The metal used in die-casting is either a lead alloy (used early on), or more commonly, Zamak (called Mazak in the UK), an alloy of zinc with small quantities of aluminium and copper. Lead or iron are impurities that must be carefully avoided in Zamac, as they give rise to a deterioration of the metal most commonly called zinc pest. The terms white metal or pot metal are also used when applied to alloys based more on lead or iron. The most common die-cast vehicles are scale models of automobiles, aircraft, military vehicles, construction equipment, and trains, although almost anything can be produced by this method, like Monopoly game pieces, furniture handles, or metal garden sprinklers.