SPD V2 kontrollklapp Full flow AN6-AN8 must

SPD full flow check valve. Used to AEM 380L fuel pumps if you have several PWM controlled.

This check valve prevents fuel pressure from dropping when you use several pumps starting up in stages.

AN6 – AN8

This non-return valve does not limit the flow.
This non-return valve makes the car easy to start as it keeps the fuel pressure when the car is switched off.