This aluminum adapter has 18x1.5mm male threads on one end and a 12AN male (1 1/16-12 thread, 37° flare) on the other. Anodizing color may vary from photo.
This adapter will also fit the inlet side of the Bosch "044" (FP200) fuel pump or the newer Bosch FP200-7 Fuel Pump when used with a Crush Washer (Part No. 3278-M18, sold separately).
Convex vs Concave