Summary: from the bike The hollow bolt between the two thick ends of the linkages is replaced as the adjustable linkages have a different one to fit the kit and come with its own connection bolt The new adjustable linkages are shown installed on the bike As you can see the linkages are threaded steel rods In this picture you can also see the Eibach 1000 lbs spring red
Image Dimensions: 800 x 533
Image originally found here.