Don't touch it with a barge pole.
They sell a similar thing on ebay. but IMO rubbish
The theory is that it basically tricks the computer into running rich all the time, and so they reckon extra fuel is extra power. This version is meant to be more trick so that you can dial in the extra fuel.
Heard horror stories of these being fitted, basically all that extra fuel kills catalyic convertors, foul spark plugs, washes the bores of lube, ups your fuel bill.
Others may have comments but to my mind your much better off spending the bit more and getting a chip which is mapped for the coupe. The evo cars one is about 85euro I think,
There is heaps of info on the site about chips have a search.
cheers