Korg VPT-1 Vocal Pitch Trainer , Handheld tuner for singers, Vertical layout, Display with staff lines (G and F clef), 3 Levels of difficulty adjustable (accuracy of the tone evaluation), Sound out function: A2 - C6, Sound back function: A1 - C7, Internal microphone, Headphone jack, Dimensions (W x D x H): 60 x 100 x 16 mm, Battery life: up to 300 hours (with 2 AAA alkaline batteries)