The rear endlinks connects the sway bar to the trailing arm on the rear suspension of your car - a piece that often fails or flexes when you upgrade your rear sway bar. The ALTA endlinks make a "No-Flex" connection between these components and in turn makes for a more predictable and better handling car.
They are also adjustable to control the amount of pre-load on your rear sway bar. This is helpful for adjusting how "strong" you want your rear sway bar to actually be, as these endlinks reduce the amount of play between your sway bar and your chassis.
They are made of high quality 6061T6 aluminum and heavy texture powder coated for corrosion protection.