ammoon 3 in1 Digital Tuner + Metronome + Tone Generator Universal Portable for Chromatic Guitar Bass Violin Multifunctional design, worked as Tuner & Metronome & Tone Generator, good helper for the novices and professionals. Mini in size, convenient to carry along. Dual pickup mode, Internal Microphone or Pickup cable. With stand on the back to stand on the flat stably. Send out sound to indicate tempo.Has connector for connecting to earphone.(earphone is not included)