jamesincIt's part of a hot start kit, it's also supposed to include a solenoid. When the car is off, the solenoid blocks the fuel bowl vent to prevent hard starting/vapourlock.
I have a broken one, tbh I don't think you need it, if you're doing a hot start just open the throttle a bit
Guess you're right.
What do you think about Pierburg 175 CD turbo carb instead of turbo Stromberg 175 CD?