Technical specifications Scale: 12-note equal temperament, programmable (88 notes) Detection Range: A0 (27.50 Hz) - C8 (4186.01 Hz) Reference Tone: C2 (65.41 Hz) - C6 (1046.50 Hz) Tuner Modes: Meter Mode (AUTO), Focus Tune (AUTO), Sound Out (MANUAL), Sound Back (AUTO) Calibration Range: A4 = 410 Hz - 480 Hz (1 Hz steps) Detection Accuracy: Less than +1.0 cent Sound Accuracy: Less than +1.5 cent Connections: INPUT jack (1/4” mono), HEADPHONE jack (1/8” mini), DC IN (9V) Speaker: Dynamic speaker (16 mm x 35 mm) Power Supply: Two alkaline batteries (3V) or AC adapter (B@&0 ) Battery Life: Tuner ... About 60 hours (alkaline batteries, Meter Mode, A4 continuous signal input and backlight off) Dimensions: 101 (W) x 84 (D) x 22 (H) mm (closed) 3.98 (W) x 3.31 (D) x 0.81 (H) inches (closed) Weight: 148 g / 5.22 oz. (batteries included) Included items: User Manual, two trial AAA batteries, soft case. Options (sold separately): AC adapter (BHO)