So I ordered one from ebay and of course it didn't come with the nut to screw into it and the car. I know I have seen other members with it on their s2ks. Do you know the thread and size of the double sided bolt?(what is its official name)

 

humbles2k says it doesn't need a nut. It should have come with four different adapter screws, one of them fits the S. Screw it all the way in into the stubby antenna and then screw the other end into the car. It's a two-sided screw adapter.

 

Yeah I emailed em they didn't send me a set. lol it is on its way now.