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.