PitchBoy(TM) is the new pocket-size, keychain mini tuner that's great for musicians on the go. Its small size, easy-to-read display, speed, and accuracy make PitchBoy a perfect fit for anyone in search of a chromatic guitar or bass tuner. Features include: Chromatic tuner Built-in microphone Includes FREE bonus eMedia guitar and bass lessons Auto-off function for battery saving 3-color backlit display (flat, sharp, and in-tune) Battery included (CR2032) Dimensions: 1 3/4" x 1" x 1/4".