This 1kHz 94/114dB professional sound calibrator is for 0.5 inch. or 1 in. microphones. Calibrates and checks the sound level meter's operation. Level switch for 94dB or 114dB with power on LED indicator light. The die-cast aluminum enclosure produces a 1kHz sine wave at 94dB/114dB with an accuracy of 5% for frequency and ±0.5dB (94dB)/±1.0dB (114dB). Meets IEC 60942 1997-11. Comes with two 9V batteries, a carrying box, and a screwdriver.