Air preparation equipment in classical design and of proven quality. Filters, microfilters, pressure regulators, lubricators, filter pressure regulators and combination maintenance units with many variations in filter fineness, drain valves, pressure ranges or bowls. Connection to maintenance units by means of double nipples. Six sizes with connecting threads G 1/8 to G 2, up to max. 60 bar. Air treatment equipment of the standard series, which can not be used for maintenance units. Filters and microfilters 40 bar and 60 bar, small pressure regulators, pressure regulators 40 bar, high pressure regulators 60 bar, pressure line regulators, precision pressure regulators, pressure regulators with internal gauge in setting knob, water pressure regulators, small lubricators.