I purchased this thing originally to be used as an expression pedal.  It is supposed to be a stereo volume pedal and a dual expression pedal.  What I don't like about it is the expression pedal option is virtually useless.  The main issue is the volume "jumps" from 0 to around 25 before continuing up, thus making it useless for "swells" or control of any parameter.   I have tried this on my computer audio programs, hardware synths and even my KORG TR and my KORG X5DR.  The problem persists on all of them.  What I do like is that it has a nice metal chassis and stereo audio inputs.  I have read that some people think there is signal degradation from this unit but I have not noticed any myself.  There is also a feature that lets you adjust the range of the pedal with a little knob on the right and also a physical screw option that does the same thing.  I don't really use either option but they are neat features none the less.  I paid around $90 for this unit used, it goes around $125 new.  Had the expression option worked, it would be worth every penny, but if you are just looking for a stereo volume pedal, I would spend my money on a stereo Ernie Ball pedal.  Same concept but less money.  As I mentioned earlier, I have read a review before that stated there was some signal degradation but I haven't noticed.  It sounds clean and clear to me.  I own an Ernie Ball mono volume pedal.  They are pretty much the same quality in my opinion.  No, I wouldn't buy this one again. The fact that the expression option is useless, even on other KORG products, I do not recommend this pedal.  The volume pedal option works fine but there is no reason to pass up a stereo Ernie ball pedal for $20 less.