Donner’s 3-in-1 digital metronome-tuner packs a patent-pending Trainer Rhythm Mode whose built-in microphone listens to every note you play, flashes real-time LED feedback and scores your accuracy for blind-beat drills, plus a one-tap tempo detector that instantly shows the BPM of any song; the chromatic tuner spans 430-450 Hz, offers quick-access C/G/U/B/V instrument presets and tunes acoustic & electric guitars, bass, ukulele, mandolin, violin, piano and wind horns with ±0.5-cent precision; the metronome section runs 30-280 BPM, 0-9 beats, 3 instrument sounds plus a human voice count, adjustable volume and a 3.5 mm headphone jack for silent practice; side “MENU” (C) and Up/Down keys let you micro-shift pitch on the fly.