In this type of cleaner, coarse woollen cloth is used along with paper, which remains soaked in oil. Its elements is covered by a thin-wire net and is fitted in a tin cover. Oil bath type air cleaner: A fine wire mesh or thin scraps of iron are used as element in this type of air cleaner. It remains partly soaked in oil. Air first comes in contact with the oil in the air inlet built in the cover and the dust particles mixed in the air are retained in the oil. Then this air goes into the air horn after having been filtered in the air filter element. This filter is used in the heavy vehicles. Air is completely filtered in this process.