RSS High Performance Tarmac Series Suspension Components are designed, engineered and manufactured on location here in the USA. RSS Tarmac Series Control Arms are manufactured from 6061 aerospace grade billet aluminum. This allows for a more uniform molecular structure at every point of the arm over the cast motorsports arm giving the customer a more durable and inherently stronger part. Manufacturing from billet aluminum rather than casting results in less impurities in the metal. Completely serviceable – for the extreme, repetitive track-day participant, our high-strength steel alloy spherical bearings (with a friction reducing / longevity increasing Teflon liner) can be replaced unlike the motorsports arm, in which case the customer will have to buy a new set of arms if the spherical bearings are worn. Additionally, anodized surfaces and zinc-plated steel parts allow for better corrosion resistance against the elements. Adjustable suspension geometry – adjust dynamic camber values and roll center heights with our unique zinc-plated steel bushings. Solid monoball control arm ends offer a more responsive suspension over the factory one-piece rubber-injected control arm (also uses the same high strength steel alloy spherical bearing found in our control arm monoball kit). Unique design provides more gusseting over the motorsports arms for added strength and aesthetically appealing looks. (LOWER CONTROL ARM – FITMENT NOTES) RSS Tarmac Series Lower Control Arms are designed specifically for lowered vehicles that are set at European Ride Height or Lower (986-996 All) and PASM Ride Height or Lower (987-997 All). They are not compatible with the (Higher) Base Model Suspensions. If you need assistance in identifying your suspension type please contact us. For more fitment information refer to the “Chassis Fitment Guide” (See Images Below). Off road use only.