Variable-Frequency DriveChina 10HP-100HP 116psi 145psi Pm VSD Two Stage Super Energy Saving Industrial Variable Frequency Drive Twin Screw Type Air Compressor with Two Permanent Magnet Motor, Find details about China Ingersoll Rand Air Compressors, Double Screw Air Compressor from 10HP-100HP 116psi 145psi Pm VSD Two Stage Super Energy Saving Industrial Variable Frequency Drive Twin Screw Type Air Compressor with Two Permanent Magnet Motor