OEM Aprilia Cam Tower Bolt Crush Washer - 857042 (857042)
OEM Aprilia Cam Tower Bolt Crush Washer, M6 - 857042
For '11-'19 Tuono V4 (all variants) and '09-'19 RSV4 (all variants)
Aprilia calls to replace these M6 x 10 x 1.5 crush washers when doing valve adjustments on any V4 engine.
Sold each. Total of 8 required to do an entire engine.