The headset will not charge if plugged into both iPhone 4 and headset at the same time. The headset will charge on it's own with this cable and the iPhone 4 will charge on it's own via this cable. Works fine for the iPhone 3GS.
Only a tiny bit bigger than the normal USB adapter cable, but with the benefit of plugging both your headset and iphone in to charge. Works perfectly, great product.
That being said, I think they could have really included this cable with the headset as standard. The Apple way is the expensive way, but I love the products so guess it's just something I have to live with.
doesnt work with universal dock tried it. Apple should bring out another dual dock that works in conjunction with this and the 3G or 3GS Phone....... I have just upgraded and now I have to sell all my iphone docks including my Dual/bluetooth dock as the 3GS will not fit into it!!! .. and neither does this charger/wire attachment fit and charge though the Universal dock ... so you cant charge the phone on the dock and the headset together..