GE Ruska Instrument Corporation 7750i Laboratory Air Data Test Set, with IEEE-488 interface, NIST traceable calibration, manual, power cord. Standard Ranges: Ps: 100inHg Abs Qc: 68inHg Diff. Ps: 32inHg Abs Qc: 68inHg Diff. Ps: 40inHg Abs Qc: 68inHg Diff. Ps: 32inHg Abs