If you own a stringed musical instrument, it is a good idea to have an electronic tuner. It certainly makes tuning a lot easier. The electronic tuner we have for sale is the Korg CA-1 Chromatic Tuner. This compact tuner would fit easily in any instrument case. It operates in both meter (automatic) and sound (manual) modes. It uses two AAA batteries that last approximately 100 hours. It is 4.1" wide x 2.52" tall x .6" high. The default setting (and mandatory setting for accurate pitch) is calibrated at 440 Hz.