General Radio Company 1521-B Sound Level Meter Graphic Level Chart Recorder

NOS Vintage General Radio Sound-Level Calibrator 1552-B with Original Box

GENERAL RADIO COMPANY 1551-C SOUND LEVEL METER w/ 1560-P5 MICROPHONE

NEW General Radio 1558-A Octave Band Noise Analyzer

GENERAL RADIO 1552-B SOUND LEVEL CALIBRATOR

General Radio 1551-C Sound Level Meter with 1560-P5 Mic and Case

General Radio Company 1551-C Sound Level Meter

General Radio 1551-C Sound Level Meter with 1971-9605 Mic and Case - Lab Tested