I'm an *always-on* tuner user, because I play violin a bunch of the time, so I am always checking to see if I'm hearing correctly. The Boss TU-2 and 3 have proved to track best and survive being always on during the concert, and since I never turn it off to mute myself (volume pedal or A/B switch) it was perfect that they made one with no "pedal" part, just the tuner. It's great, I love it, I bought two.