Well, I went to replace the wheels on my car, and found the rear wheels had hubcentric spacers on them, which don't fit my new wheels and don't allow the plastic ring spacers that came with them to seat, so I figure they've gotta go. Problem is, they've got these weird countersunk 4-hole nuts around the studs that hold the thing down.

The previous owner was nice enough to leave the adaptor for a 13/16 tool in the car, completely broken. Does anyone know what I'm talking about and what those nuts are called? I need to locate an adaptor for removing them, but it's hard when you have no idea what to call the thing.

The best I can do to describe it is, the nut appears conical and has 4 small holes in a square pattern around the center hole that goes on the stud. When completely screwed in, they sit flush with the spacer. The removal tool is just a 13/16 hex head cylinder which fits around the post, and appears to have had 4 tiny protrusions from the bottom to mate with the nut, until the previous owner sheered them off...

 

pictures will help

 

You're looking for a four prong lug key for the wheel spacer, pictured below.

It would be helpful to know who made the spacer but I've seen companies like Project Kics and TC Sportline sell them individually.
Not sure if it will fit but a quick google search found this: http://www.shop.upgrademotoring.com/...?productId=380 (I can't speak for the reputation of this company)

 

That looks to be about what I'm looking for. Thanks!