Fluke 5101B Calibrator: Automatic calibrator with built-in mini-cassette deck for procedure storage. Calibrates DC voltage, AC voltage, DC current, AC current. Unit has all voltages, currents, frequencies and resistances needed to calibrate analog and digital multimeters. Opt. 03: Wide band AC voltage. Opt. 05: IEEE-488 interface. Opt. 06: EIA RS-232 interface.