Stock non-M arms are made from sheet metal that is merely spot welded together, which tends to flex and bend under moderate loads let alone track day or racing stresses. If you use grippier tires and an engine with more torque, then the stock arms aren't able to provide stability and consistent handling.  SPL Parts Titanium Series Rear Guide (Traction) Links (RGL) feature gundrilled 2024 Aluminum links that are Black Anodized to prevent corrosion and provide a durable finish. Our exclusive 360 rotating 6061-T6 Aluminum Clamps allow quick, precise adjustment with Blue Anodized Titanium Socket Head Cap Screws, which shaves even more unsprung weight without compromising strength. Custom 3 piece FK Bearings Rod Ends manufactured in Connecticut feature a Teflon liner to provide quiet operation, low friction, smooth articulation, and eliminates bushing deflection under load. The PTFE linet is chemically bonded to the inner diameter of the race. The liner offers a very high load carrying capacity and has greatly increased dynamic wear characteristics. The operating temperatures of the liner ranges from -65º to 325ºF, offering robust reliability for both street and track use.  Sold as a pair.  Made in the USA.  SPL Parts Rear Guide Links for BMW E8X/E9X Features: Black Anodized and Gundrilled 2024 Aluminum Links 6061-T6 Aluminum Clamps Blue Anodized Titanium Socket Head Cap Screws Tapered Stainless Steel Knuckle Mount Spacers Teflon lined FK Rod Ends Applications: E8X 1 Series BMW M and non ME9X 3 Series BMW M and non MNote:  It is recommended to keep this arm set to OEM length.