The advert for this cable is a complete scam!
As already mentioned HDMI is a digital only connection and Component via 3 phono plugs is an analogue only connection. HDMI can IIRC tranfer digital component video signals, but never analogue component.
Then there is the dact that it is listed as 'HDMI to Component Video with Stereo Audio AV Cable 1M' and shows a picture with HDMI plug one end and just 3 (Red, Green & Blue) phono plugs the other - so where are the audio connections then? So even if the digital to analogue conversion was possible in just a cable it would only be outputting the component video or composite plus stereo audio (but the phono plugs are the wrong colours for this)
Ho Hum, I bet there are people out there that wont realise and will part with money for this item
Mark.