e30 - what is this hose?

[EastCoastErik]

Mine has rotted. I can't figure out what it is. Does anyone know the part number? Hose Diameter? Anything?

[Vincenze]

It's a fuel tank ventilation hose.
https://www.realoem.com/bmw/enUS/sho...diagId=16_0107

I believe <1987 cars had fuel pumps with 2 outlets.