This is, by far, the best tuner pedal on the market. I can't remember who pointed it to me to it when Vary Mary was playing regularly, I thought it was here. Best pedal I ever bought. Its Poly, so you can strum all 6 strings at once and 6 red lights go across the top with green lights above and below that show if any are out of tune and roughly by how much. So you see the G string is a little sharp, it's always the G string, and when you pick just that string, the big, bright G shows on the display and you have multiple options for how you want it to indicate the tuning - including strobe. On top of all that it has a built in buffer, which you should have at the beginning of any chain of 3 or more pedals anyway, and it's form factor is smaller than most other tuner pedals.this replaced both a bigger Poly tuner I had and a buffer, and does a better job at both. I do use mine as a big on/off switch. It's true bypass. You do want it. I have a lot more guitars (13-ish) than I do basses (2), but the tuner pedal plays great w all of them. Edit - it's green lights for in tune in Poly mode, like this.