I bought this pedal to help create ambient swells and take the job away from my volume control on the guitar.
I did a bit of research, and the main reason I bought this particular pedal was that there was no power supply required. I have a behringer expression pedal that I had some difficulty with, mainly due to having to buy a separate power supply because when I ran it off the Harley Benton Powerplant, it wasn't a happy camper at all.
Anyway, the FV-500-H got great reviews online as far as volume pedals go, and, like I say, no power supply required.
I didn't have any problem with it at all until I bought a BCB-60 pedal board, when I was disappointed to discover that it is that little bit too big to fit inside, even after removing the particular part that would allow for a wah pedal or some such. No big deal, as I would've had to evict more important pedals to allow for it anyway.
The FV-500 is reasonably heavy, quite sturdy, and feels just fine under foot. It is possible to adjust the overall feel and indeed even the volume range. Overall, I am quite happy with this purchase because it is of great quality and does exactly what it is supposed to do.