The ball joint is stainless steel with custom cnc machine sleeves. These camber kits are great for correcting negative camber - when the top of the wheel is tipped in towards the body. Camber is the tilt of the wheel along its vertical axis. Running wider tires or car with lowering springs can cause this issue where your tires are wearing out on the inside. They are also great for older cars where the suspension tends to sag hence the wheel looks "spray out".
To some degree, this is a good thing as it allows more of the tire tread to stay in contact with the ground during hard cornering. But if you have too much negative camber, which degrades cornering performance as well as hinders grip during hard acceleration. The camber kit can straighten the wheels by dialing out the negative camber, something you can't do with the stock suspension. Like wise, if you want more negative camber, this kit can put the wheel further in, allowing more camber for those of you who would like to have the "tuck-in" and slammed look. The arms come with either red or black bushings.
Please let me know which color do you want when ordering. The default color would be black. Please let me know what model R230 you have on the note section when you order so I can get you the correct configuration. The item "Mercedes Adjustable Front A-arm Camber Kit R230 SL550 SL550 SL55 SL63 ABC" is in sale since Friday, April 16, 2021.This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Suspension & Steering\Caster/Camber Kits". The seller is "snooozie" and is located in Plantsville, Connecticut. This item can be shipped worldwide.