Kaeser Compressors introduces Sigma Screw Compressors with the Sigma Frequency Control (SFC). This variable speed drive device was designed to achieve maximum efficiency over a wide flow range. Standard SFC compressor packages are available from 100-215 hp and flows from 130-1001 cfm providing measures from 80-145 psig. Kaeser's SFC can run fully loaded - indefinitely - if your application requires it.