www.mcgard.com. Look in the drag racing section. I'm sure you'll also find them at Summit Racing. NHRA and other sanctioning bodies require open lug nuts so the tech crews and check for adequate stud engagement. -Bigchief.
I just bought some of these at Krager (I think they go by other names back east, look at the website). They are cheap... Chrome and have the hole that goes through.... Six packs I think Hyfire