This Hiden Analytical HAL 201 Quadrupole Residual Gas Analyzer is a reliable tool for measuring gas concentrations in various environments. The brand Hiden is known for its quality products, and this analyzer is no exception. It is perfect for use in gas and combustion analyzers, as well as in other industries for test, measurement, and inspection purposes. The unit is easy to operate and provides accurate readings, making it a great investment for anyone in need of a reliable gas analyzer.