Sound Level Meter, Portable Digital Sound Level and Decibel Measuring Meter Tester 30 dBA-130dBA, Max/Min Hold, Hand-held LCD Backlight with Tripod thread-one 9V Battery Included The measuring range is 30  130dB, accurate to 1.5dB Records Max/Min values over time, Fast Responding; With a tripod thread, you can fix it on tripod. Two time weighting to select: you can set response to FAST when the sound source consists of short bursts, or you use the SLOW. The frequency range: 31.5 Hz to 8.5KHz, Linearity range: 50dB Powered by one 9V battery (included),you can measure constantly or auto power off without operation after 10 minutes.