9 Tools and equipment for the electronics manufacturing industry, namely, rework apparatus in the nature of apparatus for reworking specialized arrays of electronic components attached to a printed circuit board, electric soldering and desoldering apparatus for assembly of printed circuit boards and electrical circuits, computer-based apparatus for automatic assembly of electronic circuit board and electrical circuits, electric soldering irons and power supplies therefor, for assembly of circuit boards, electrical circuits and electronic components, electric-powered fume extraction units, for use in production, repair, and testing of printed circuit boards and electronic components, none of the aforesaid being for construction purposes; automated fluid-composition control instruments in the nature of dispensers, and mechanical devices in the nature of dispensers of preset portions of industrial fluids, and structural parts therefor sold as a unit, namely, dispensers, receiver heads, dispensing tips, plungers, needle adapters, end caps, seals, cartridge dispensing guns, plunger seals, flow restrictors, retaining nuts, dispensing mixers, dispensing pens, dispensing controllers, pressure dispensers, adapters, for use in electronic assembly and repair, and tool fabrication, assembly, and encapsulation