The Sper Scientific Mini Sound Meter is packed with features, yet it is small and light enough to be carried in your shirt pocket. Choose from fast or slow time weightings, min/max readings and A or C decibel frequency weighting scales. All of these settings are simultaneously displayed on a large 1¼” backlit display. Also features hold, and auto-power off. Readings are extremely stable and reliable. Reference to IEC651 and ANSI S1.4 standards for type 2 sound level meters. Auto-ranging 30 ~ 130 dB (A) with 0.1 dB resolution and an accuracy of ±1.5 dB (Ref. 94dB@1KHz). Can be calibrated, in compliance with OSHA, using Acoustical Calibrator 850016 or equivalent. The Sper Scientific Mini Sound Meter comes ready to use with a windscreen, instructions and 9V battery. N.I.S.T. traceable certificate of calibration available. Dimensions: 8" × 2⅛" × 1½" (203 × 54 × 38 mm) Weight: 5.8 oz (164 g) .