Filters for hydraulic [ and pneumatic ] power units in industrial, construction and agricultural machines and for vehicles, and replacement parts therefor, namely, liquid filters, [ gas filters, multistage filters, change-over filters, ] filter elements, [ filter candles, ] filter cartridges [, filter shells, filter disks, filter mats, filter pots, filter cloths, filter bags, and filter belts; liquid and gas filters of plastic as parts of engines or motors ]