If you look up the iLuv iHP636 ReF on Amazon, you'll notice that its full, extended name includes the descriptor "Deep Bass On-Ear Headphones with Canvas Fabric Exterior for Smartphones."
It would seem, then, that this headphone has been designed to offer a lot of bass -- and that it certainly does. It's also comfortable for an on-ear model, with nicely cushioned earcups and a foldable design. The only problem with it is that it falls short in the clarity department, which keeps it from being a really good headphone.
Design and features
The ReF, available in multiple colors, is a bit of a riff on a common design you've probably seen for on-ear models. Urban Ears made it popular, and several other companies have offered modified versions of it.
That said, this model does have a more premium quality to it, with -- yes -- canvas fabric on the earcups and the headband; also, there's some faux suede on the interior of the headband. As I said, the earcups are nicely padded (iLuv says there's Memory Foam inside, even if it doesn't quite feel like it) and offer a tight seal, which helps muffle ambient noise. The headphones do fold up, though not flat.
Overall, the construction seem sturdy, and the cord is cloth covered (it looks like a shoelace and is tangle-resistant) and terminates in an L-shaped plug. That cord should hold well, but if it rubs against your clothing, it can make some noise. That bothers some people more than others.
In terms of extra features, you get an Apple-friendly inline remote/microphone that's compatible with iOS devices but won't fully function with Android and other phones (you should be able to still make calls using the microphone, but the remote's features probably won't work).