Standard master cylinder to slave cylinder hose. Note: the real problem with this flexible hose is not visible from the outside. The problem occurs after time as the inside of the rubber hose begins to absorb brake fluid and swells up. There is no way to see this from the outside. The result is that fluid that is forced to push the clutch rod under pedal/hydraulic pressure is expected to return with only the help of the 'return spring'! As the line swells the passage way gets smaller and smaller until the clutch engages so slowly that it feels as though it is slipping! When doing maintenance alwyas replace this line!