Funktion is right. Also if you would have read the karcepts instructions its tells you to use a 06-11 civic si passenger oem axle. DO NOT use an autoparts store axle!! if you review my ek build thread just below yours I literally when threw this a few months ago.I recommend the si axle. Cheap and easy. Best way to find them on eBay is to search by the part interchange number. You get more results and find ones less expensive.