“C” SHAPED OPTICAL FIBRE

16:58 Feb 14, 2020 

• Bring forward with the centre, using knob M1 until the radius of the optical fibre is positioned exactly between the cage and the outer ring of the bearing or on the sticker ( “blind” bearings ).

16:53 Feb 14, 2020 

OK, then — so what does it go on to say about it under the header? We don't need other occurrences of the same term, but simply what is said about it where it does occur.

08:16 Feb 14, 2020 

This is an instruction booklet for a demagnetiser, it only comes up once so unfortunately not much to say.."C" SHAPED OPTICAL FIBRE AJUSTMENT is a header

22:46 Feb 13, 2020 

I think we won't be able to help unless we know more about where / how / what this items is used for.
It seems to me unlikely to be a C-shaped cross section — by their natural fibres tend to be round, unless of course this is a 'cable' made up of several fibres arranged in a C-shape...
But my gut feeling is that it will probably be a short length of fibre, bent round into a C-shape — remember, with optical finres, minimum bend radius and flexing strain are key issues; so this may be in come way explaining how these problems are addressed using some sort of loop of fibre...