Features2 modes provide 2.5dB or 3.5dB accuracy A and C weighting: high and low measuring ranges: low (35 to 100dB) / high (65 to 130dB) 0.1dB resolution fast/slow response data hold and max hold function large 3 1/2-digit LCD display with function indication built-in calibration check (94dB) complete with 9V battery and carrying case Specificationspower supply: 1 x 9V battery (incl.) dimensions: 225 x 58 x 33mm weight: 250g auxilary outputs: AC/DC signal output