This 1kHz, 94dB professional sound calibrator for 0.5" or 1.0" microphones calibrates and verifies sound level meter operation. Battery test position with battery status LED indicates if battery is good. Durable die-cast aluminum housing generates a 1kHz sine wave at 94dB to an accuracy of 5% (frequency) and ±0.5dB (94dB). Meets IEC standard 60942 1997-11. Complete with two 9V batteries, carrying case, and screwdriver. Includes certificate traceable to NIST.