One of the issues that some current riders run into when switching to Ducati from Japanese sportbikes is that Ducs shift differently.
They require a lot more foot pressure to move the shift lever. Some would sayToo much pressure.
For when you decide that you want lighter feeling shift lever action for better feel. A lighter foot shift pressure is less unsettling. Decreases lever effort required to make a shift. Makes foot shift pressure more like other sportbikes. Find neutral easier.
If you like your fancy rearsets, but no matter how you lube, shim, adjust the arcs, angles and lengths, it's still annoyingly stiff to shift? Get this spring. (this is not the Pro Shift Detent Kit - that is a different kit)