A little about control arms from RC

If you have RC control arms then you'll know that X-Flex joints pivot up to 20 degrees, while lower arm joints are capable of a staggering 35 degrees pivot range. These great features mean that the product from Rough Country guarantees durability and greater safety in off-road applications.
Service part

You do not have to replace the entire control arm if the service part is already to be replaced. The X-Flex system provides the option of rebuilding or replacing the end of control arm alone together with the uniball. The fully lubricatable joint have a much longer service life than the original ones.

Specs:

    Fully greasable
    Provides greater twist
    Ensure a much longer life than the original ones