Fuel tank OE number 9141101 and/or filling pipe 9141120 -> hose 3531434
(https://www.skandix.de/en/spare-parts/body/body-parts/fuel-tank-filling/breather-hose-fuel-tank/1041811/)
Other tanks with filling pipe 9447039 -> hose 1047400
(https://www.skandix.de/en/spare-parts/body/body-parts/fuel-tank-filling/breather-hose-fuel-tank/1047400/)