These floating top hats allow the damper shaft and the spring to remain in perfect alignment regardless of the top mount of the chassis. This eliminates any bending loads from the damper shaft. 

Keeping the spring perfectly perpendicular in compression keeps the spring rate perfectly consistent (especially important on track where predictability of spring rate is essential through the compression range). 

Most importantly for the Ohlins DFV is the translation of linear shock velocity directly to the piston - which actively changes damping force based on shock velocity (low-speed, high-speed, and ultra-high-speed "blow off"). The standard Tesla top hat has a rubber/foam insert (a spring) that is in line with the shaft. This induces a delay in the translation of the wheel movement to the piston itself, delaying it's response. The end result of using these floating top hats is a further increase in damping accuracy over bumps and more control. 

There may be a very small increase in NVH with these fitted.

Sold as a complete set of 4 (front and rear, left and right).