The FastFlo 620S is an insertion thermal mass air flow sensor designed to give you a highly reliable, responsive and affordable mass flow measurement for light industrial applications where a NEMA 4X (IP65) enclosure is acceptable. Sierra Instruments is a global leader in fluid flow measurement and control for nearly 40 years and is known for its high performance flow instrumentation for gas, liquid and steam applications commonly found in the semiconductor, environmental, scientific research, petrochemical, energy, aerospace, and general manufacturing industries. With over 150 locations in over 50 countries, Sierra is positioned to support customers across the globe to solve tough flow problems.