ey with continuously variable cutoff frequency 35 337 selection from 50 - 500 Hz (defeatable). 36 392 Infrasonic Fitter: 37 426 24 dB/octave Butterworth 0 30 Hz (defeatable). 38 `50091 447 39 467 Preamp Output: Full-dodavlse: 470 Buffered pass-through type. Dimensions(LxWxH): 8.52- x 7.09' x 2.05