The SL510 is Extech’s ultra-compact sound meter which meets class 2 standards with ±1dB high accuracy. Allows for quick and reliable sound level testing. It features a large backlit display for easy viewing and measures A & C weighting from 35 to 130dB with Fast and Slow response time mode. Size is small enough to conveniently fit in your pocket and includes a wrist strap. Complete with microphone wind-screen, and three AAA batteries.