what it do really? it looks like an extender,
You need a TRRS adaptor, which reverses the microphone and ground pins. : http://www.amazon.co...2&keywords=trrs . With this you'll be able to use any headset with your V5. You can find it cheaper on eBay but the cable is too long, or maybe I haven't searched around enough. I have a Turtle Beach M5 headset and luckily the adaptor came with it.
I have a pair of kannen earpones with mic and not work good, genuine samsung and sony ericson works, and any earphone with NO mic works good...
I dont know why