They are called MDR-D333F for some reason, but I guess it is because they can also be used as a headset for Sony Ericsson phones. They cost $4 more than the D333LWs because of this extra feature, but they still have a regular jack so you can still use them like normal phones. Anyways, even if the SE compatibility feature is worthless to you, even with the four dollar premium, its good for those people (like me) who have held off on these because they did not come in black like the old D66.

http://www.audiocubes.com/category/Headpho...Headphones.html