I bought this initially for one particular use. I was frustrated with iPad synths which I was triggering via MIDI because although a lot of them sounded great, I wanted to have velocity controlling filter cutoff or amplitude as I generally do on my hardware synths. This little box allowed me to do just that, as it can translate velocity info into two different MIDI CC values for you if required, while still allowing the original note data to pass through if required. I can't summarize the capabilities of this unit in a paragraph or even a page. It lets you turn one kind of MIDI information into another, and change the channel at the same time. You can turn note-on data into CCs, you can set a range so that certain values trigger a MIDI event...the list is endless. Since I got this unit I have found it to be a lifesaver in my studio to sort out a variety of communication problems between MIDI devices old and new, and it has allowed me to set up patches for live performance which would have been impossible otherwise. My one complaint is that it has to be MIDI-powered, and that most devices and controllers these days do not supply enough power to their MIDI outputs to power the unit. It would have made life a bit easier if they had just put a DC input for an external power supply on these little boxes, because every time I use them I have to plan a patch with this in mind, or use a powered MIDI-thru box before them in the chain.