LARGE Particle Counters Large Particle Counters: Remote, Benchtop,and Handheld Model 5501-30 0.5 – 75 µm @ 0.1 CFM with internal pump More Info Model 7501-30 0.5 – 75 µm @ 0.1 CFM with internal pump and battery More Info Model 8506-30 0.5 – 75 µm @ 0.1 CFM with internal pump and battery More Info