The Prova End links all feature a spherical load bearing to increase the energy transfer from the sway bar to the lateral link or control arm. The majority of factory Subaru End Links are made out of a flexible plastic and are designed to absorb a lot of the vibration and flex that occurs during aggressive driving conditions. The Factory Endlinks are weak and are notorious for breaking with upgraded sway bars.
The Prova End Links are designed to be a direct replacement for these stock links. The sway bar performance is immediately increased with the change of these End Links. These end links are a Motorsports Product and can produce function noise while moving.