Advanced R&D UTI Quadrupole Mass Spectrometer 4-1/2" CF UHV flange, 300 mass units, variable scan control, variable mass range, 3 preset mass ranges, uses channel electron multiplier ( CEM ), 10-5 to 10-12 amp ranges. Ion source and / or SIMS prefilter. RF generator, control electronics, preamplifier. Excellent buy for the performance.