The Dean Markley PT-13 is a chromatic tuner pedal designed for use with electric guitar and bass guitar and suitable for use with any electronic instrument you might need to tune. It's definitely designed for live shows, although it's useful in the studio or practicing at home as well. It's clearly Dean Markley's take on the infamous Boss TU-2 tuner pedal that's of a similar nature to this. The PT-13 doesn't give you as many options as the TU-2 and isn't as well designed, but it's a tradeoff in the price. The pedal has 1/4" connections for input, output, and bypass, and requires power from a nine volt battery. It's certainly not rackable in any way as it's a foot controlled pedal. You can choose the pitch you'd like to tune to or use it chromatically and have it recognize which note you're closest to. I've only used it in the latter mode which I find is quite easy. I've only used the pedal in the studio as a band on a recent session had one, but again I still think it's most useful on the stage as it's got all LED lights so you can see it in the dark easiest. For anyone playing live it's a must have to have something like the PT-13 or TU-2 that you can tune with in the dark. It's easy enough to tune with the PT-13, but you're also lacking the ability to power up other pedals like you get with the TU-2, and I also find the TU-2 just to be easier and cleaner to use in general. Of course the TU-2 is more than double the price of the PT-13, so it all comes down to that. The PT-13 isn't as sturdy or well built as the TU-2, but as always you're going to get what you pay for. If you have a lot of pedals you want to power up, I'd go with the TU-2 but if you just want a really simple tuner for a cheap price, the PT-13 will do the trick fine.