Genuine Honda fuel hose, sold as a 3 Meter / 10 Foot Roll. This is typically used on the brass fittings at the base of the carburetor (overflow lines). It was also used as vent lines on many of the SOHC carburetors, these are the two lines that run up over the airbox.

We also have 5.5mm Genuine Honda fuel line that was used from the petcock to the carbs.

Honda Part: 95001-35003-60M
Dimensions: I.D. 3.5mm - O.D. 7.5mm