#2
The TU-12 isnt chromatic, whereas the 12h and 15 are. Chromatic means they do more notes than those possible on a guitar or bass and you can tune other instruments as well. The 15 also looks like it has presets for different tunings like drop D, and stuff. Look at the links below to look at it specifically.

http://accessories.musiciansfriend.com/product/Boss-TU12-Tuner?sku=151356
http://accessories.musiciansfriend.com/product/Boss-TU12H-HighRange-Chromatic-Tuner?sku=151357
http://accessories.musiciansfriend.com/product/Boss-TU15-Chromatic-Tuner-with-AccuPitch?sku=213013
#3
Quote by Chaos Nil
The TU-12 isnt chromatic, whereas the 12h and 15 are. Chromatic means they do more notes than those possible on a guitar or bass and you can tune other instruments as well. The 15 also looks like it has presets for different tunings like drop D, and stuff. Look at the links below to look at it specifically.

http://accessories.musiciansfriend.com/product/Boss-TU12-Tuner?sku=151356

There seems to be a chromatic option with the slider button. What's that about?
#4
Oh I'm sorry, it is chromatic. I'm not quite sure how that would work. I use a different very much cheaper tuner. I'm not sure how that one would work. Hopefully someone who knows how to use it can explain.