V4 Sump Plug Washer 857147
Fitment - RSV4 09-21, Tuono V4 11-21
OEM Aprilia V4 sump or oil pan plug washer, part number 857147, item 17 in the diagram.
This is an essential item to replace when you're refitting your sump plug. It's design means it will crush slightly and deform into the contours of the recess where the plug sits and create a leak free seal.
But please do not over tighten your drain plug as this will lead to the cracking of the casing and no amount of deformity of the washer will be able to cure that leak. Please see here for the correct torque setting, and many more for you to use.