Good, but not for Android
I like Sennheiser. I already have a headset for my ipod and I wanted another set, with a speaker, for my T-Mobile Android phone. These had the same 4 post jack as the crap headset that came with my phone so I took a punt. Unfortunately the wiring must be different coz they didn't work properly. My colleague has an iphone and I gave them to him to replace his stock set. He reckons they're great too.