Japanese manufacturer of random audio products. Probably out of buisiness. I've heard references to Quadraflex speakers, and I have some Quadraflex headphones. If the headphones are any indication, Quadraflex makes junk. Basically they took some 16 ohm speakers (like you would find inside your PC), and mounted them in headphones.
They are pretty nice, though, considering I got them for free. (One channel didn't work properly, but that was easily fixed with a soldering iron.) Also, the audio cable connecting the headpones to the source is not shielded, which I think is poor style.