It consists of carburettor and other molded items made by zinc, with or without iron. No burrs allowed, rusty scraps, dirt, skimmers, grease.
It consists of pure zinc without impurities in the alloy. It must be free from iron and from other -Mineral and non elements.
It consists of pure soft pencil without impurities in the alloy. Must be free from iron, and other non -Mineral elements, as well as pencil battery plates and skimmers.