Injection Molding is a manufacturing procedure used to produce huge quantities of items. It is most commonly employed in mass-production procedures when the identical item is manufactured hundreds, if not millions, of times in a row. In addition, it is also used for producing small quantities of items that are not feasible to manufacture by other means. The basic idea behind injection molding is to heat and soften a plastic material in a metal mold, squeeze out the softened material through tiny holes in the mold, and cool the resulting molded part down to room temperature. The cycle is then repeated as required. Molding is usually done with a machine called an injection molder. This kind of machine incorporates both an injector (for injecting the molten plastic into the cavity) and a ejector (for removing the finished part from the mold). Some injection molders have only one element, such as an injector or an ejector. These machines are known as single-shot molders. Others have multiple sets of injection and ejection mechanisms which allow several parts to be made at once in separate cavities. These are called multi-cavity molders. One advantage of this method is that very complex shapes can be produced easily without having to make many separate parts first. For example, a company might want to produce some simple parts first and save their more intricate designs for later.