FromHereToInfiniti is right, do a search on "grounding" and you will have plenty to read.
One thing you should be aware of is that this is not a NISMO-branded product, I think the eBay sellers put that in there so it comes up in more searches. I recently bought a set off eBay for $20 and I think it looks as good as the $100+ ones you see from MyNismo or Grubbs or whoever... see the last pic in the thread below.
http://www.infinitifx.org/phpBB2/viewto ... c&start=50
Does it work? Well that's a question you'll have to answer for yourself.
I'm not going to open up that can of worms again... :wink: