Sump Oil gauge sender unit strengthening ring, most oil level sender units (& tank sender units on DB2 & 2/4) are getting a little tired now, when you tighten up the 6 screws the face of the sender buckles & it wont seal properly.

This ring helps keep the (rare) sender unit flat & stop the face buckling, easy to fit, plated for long life & anti- corrosion.