If they are the 5 spoke "premium" alloy wheels, argent/silver colored, then they're about 21.5 or 22lbs if I remember correctly. They're almost as light as the Saleen's and much cheaper.
They are quite a bit lighter than the Bullitts. One of the lightest wheels available for our cars. It's a difference I could feel going from Bullitts to these. And if you can find a used set off craigslist or something, one of the cheapest.