Even the cheapest mobiles are incorporating MP3 playback these days, but so many of them use custom connectors (as distinct from standard 3.5mm audio jacks), and that leaves you at the mercy of the vendor, and usually just stuck with the crappy earbuds that they shipped with the phone. The HPM-85 does address the issue of crappy bundled earphones -- at least for Sony Ericsson phones, and the particular kind of custom connector that they use.
The kit comprises the silver headphones, which come with a 3.5mm connector. Before you start making big audio plans for the HPM-85, the kicker here is that the headphone cable to the 3.5mm connector measures in at a piddly 25cm; you might just reach a shirt pocket with that if you're a midget, but everyone else will either have to crane their necks or spend extra on an extension cable. The other part of the HPM-85's offering is the 3.5mm to Sony Ericsson Mobile interface cable, which also includes a simple music controller within the much lengthier cable.
The headphones themselves are quite decent in terms of audio clarity, and as they cover your entire ears, they're even passable in terms of noise reduction. As with most over-the-ear models, retained heat is still something of a comfort issue, and the slightly smaller size of the earpieces could be a problem if you've got truly gigantic ears.