A sample from the products for the 028 - Sospensione Posteriore include: Screw, Special, Rear Shock Absorber.
In this schematic the "Screw, Special" is used most often.
The most reasonably priced component used on the Hym939sp 2016 Usa (hypermotard 939sp) D230-00016 028 - Sospensione Posteriore is the Screw, Special.