Seiko SAT-501S Chromatic Digital Tuner Auto Chromatic Mode - Manual Chromatic Mode - Sound Mode A0 (27Hz) - C8 (4186Hz) - C4 - B4 (12 Notes) - A4=410Hz - 450Hz (1Hz Step) LCD Display/Analog Meter (+/-50 Cent) - Digital Cent Indication (+/-50 Cent) Calibration Indication - Mode Indication - 3 LED Tuning Guide - Octave Indication - Built-in Microphone - Input Jack - Output Jack - Auto Power Off - Memory Back Up The 2-AAA Batteries Are Included