Parts such as the 05a - Clutch-side Crankcase Cover (jap): Nut, Special, O-ring 18.64x3.53, Snap Ring, Spacer 5.2x8.4x2 are included in the Superbike 2016 My16 (superbike Panigale R) D220-00016 05a - Clutch-side Crankcase Cover (jap) parts fiche.
The Snap Ring is the cheapest item from this partsfiche.
The Ducati 05A - CLUTCH-SIDE CRANKCASE COVER (JAP) has thirty products enlisted in the schematic.