The Boss TU-12 has been an industry standard tuner for the past 25 years, but has now been surpassed by the new EX version. This tuner has a full chromatic mode as well as Guitar and Bass modes.
The VU-style meter is easily readable, and is further assisted by indicator lights. A full range of calibration options are on board, as is the ability to change the tuning pitch at the touch of a button. After a few minutes of inactivity, the tuner will automatically switch itself off in order to preserve battery life.