The Korg Pitchjack is a chromatic tuner for guitars and basses. It allows for tuning seven-string guitars (7B through 1E) and six-string basses (low B through high C). It plugs into the instrument jack and has LEDs that show the string number and tuning status. It even allows for flat tuning. It’s angle is adjustable, it has a built-in light to help you see in low-lighting situations, and you can even attach it to your keychain or gear bag. Korg has the Pitchjack, in your choice of black, white, or red, for $19.99.