94dB and 114dB Sound calibrator at 1 kHz Conforms to IEC 60942 (2003) Class 2, ANSI SI.40-1984 Accurate and simple to use Fits 1 inch and 1/2 inch microphones 1-Year WarrantyThe CAL73 sound level calibrator is used to calibrate sound level meters and other sound measurement equipment. You can calibrate 1 inch diameter microphones directly and 1/2 inch microphones using 1/2 inch adaptor supplied with the calibrator.