1.Bare fibre is an uninsulated single core made of PMMA (PolyMethylMethAcrylate) that carries cold light from the illuminator with no electricity or heat in the fibre cable. 2.Uninsulated fibre cables are used for pin point lighting in signs or star ceilings due to the main concentration of light delivered to the end of the fibre cable. Without an outer sheath, light is able to emit from its side creating a soft glow when paired with the correct light source or illuminator. 3. Fiber Optic Application:Light curtain;Fiber optic chandelier;Ceiling star;Pool light;DIY.