3 geophone channels + 1 microphone channel • Frequency range 2-250 Hz • Record length Default: 2s, expands automatically to 10s if signal is present •User selectable: 1, 2, 4, 8, 16, 32, 64 s • Sampling frequency 1000, 2000 or 4000 Hz •Measuring range ± 250 mm/s