Used Aston Martin Coolant Level Switch #1R12-37-10166.

For Aston Martin DB9, DBS V12, One-77 and others

Number 7 in this diagram: https://www.scuderiacarparts.com/part-finder/astonmartin/db9/oe/151/668/23906?h=181505

Fitted to the bottom of the Tank-Asy Expansion |4G43-19B518-BC

Good working order when removed.