The AT143 ARB Stiffener increases stiffness of the anti-roll bar up to one step.
+1 step stiffness increasings means that 1.0 mm bar acts like 1.1 mm bar
1.1 mm bar acts like 1.2 mm bar
1.2 mm bar acts like 1.3 mm bar
1.3 mm bar acts like 1.4 mm bar.
1/2  and 1/4 steps of increasing are possible to set.

See Instructions attached as picture.

contains: 

2pcs AT143

4pcs SS3X3