Thanks Chris , I actually found the OE one I had on prior
Was interested in the answer all the same , most lines I could find only where AN type braided
Just on a side note to get your insight , I fitted a new Oberon Clutch Slave the weekend, it has a rock hard Clutch lever after I bled it
Considering these are very single little units in design and to fit , I presume it is faulty
its a 2002 748s
Repro steps
Installed to the Bike and Bleed as per instructions, the bike has a rock hard Clutch lever (the Pre 2000 Push Rod Spacer was NOT used)
Unbolted the Oberon unit from the bike , to test if the piston in the Slave would move , still rock hard Clutch lever , no slave piston movement
The OEM Slave was re-installed and Bled , no issues