The Setra Systems 3301P & 3501P Series Particle Counter measures 0.3 μm to 25.0 μm through a long-life laser diode and a flow rate of 0.1 CFM (2.83 LPM) with internal vacuum pump and manifold that do not require external vacuum source. Easy to configure and with user configurable alarm light, this stainless-steel particle counter monitors 4 user-selectable size channels to allow for continuous monitoring of particulates in your critical environment.