Don't know the first thing about them TBH but price seems too good/scary to be true, however, I'm sure a more knowledgable member will be along shortly to confirm.
I know price is no guarantee of quality, but it may be indicative, as they keep the wheels on, maybe splash out a few more quid. Example below of some, generally, well reviewed nuts, to give an idea on other products and their prices
http://www.tarmacsportz.co.uk/GB/Muteki_Super_Tuner_Closed_Wheel_Nuts/350z-MutekiSTClosed.aspx