Reliable diecast aluminum housing with black-out finish provides improved contrast & visibility * Double or Single Metering; Single offers four modes: Meter, Full Strobe, Half Strobe, and Mirror * Supports 6-string bass & 7-string guitar; Open tunings (D, E, G, A); DADGAD; Five custom tunings * 9 volt/200 mA cascade output for pedalboard convenience; Battery/AC Operation; 100 % True Bypass * Highly accurate: +/- 0.1 cent; Wide E0 - C8 detection range; Calibration range from 436 Hz - 445 Hz