i need your guy's help to identify what kind of nut this is so i can take off this spacer

 

They are a specialty nut designed to be tightened from the top instead of the sides. The manufacturer of those spacers probably provided a "key" to tighten them with. The previous owner should have included it with the car, much like you'd include the wheel lock "key". If you can get the make off of them, maybe you can contact them and get one. I know I have seen them before though, so maybe you can just call around to the major manufacturers and ask; you are bound to get a hit at one of them.

 

I searched for 15mm hubcentric spacers through google and found a picture of Project kics spacers. The only website that i found that only sells the key by itself was UpgradeMotoring. Bought one for 28 bucks. Pretty expensive for a key.

 

Are you joaking? Thats really cheap for a key. I paid $60 bucks for my Rays lug key that a tire shop lost...

 

Not having the proper key for the job . . . PRICELESS!

I'm glad you at least found a source. Maybe you can still call around and find one a bit cheaper. Another thought would be to ask who makes the actual nuts for the spacer manufacturers, then go right to the source; someone like Dorman, Batco, ARP, etc.

 

Check Ichiba. I had those on mine. If you remove them, get rid of those nuts. They are garbage. I bought a pair of 15mm eBay spacers a while back and they turned out to be Ichiba. The keys break easily so they sent me a set of small lug nuts that were normal 6 point.