These attenuation coefficient values are based on the spectral results of a limited number of fibres, together with an assumption of 0.275 dB/km at 1 550 nm for the maximum attenuation coefficients and 0.210 dB/km at 1 550 nm for the minimum attenuation coefficients. Actual installed cable attenuation is statistical in nature, and these values should not be taken as specification limits on individual fibres, cable sections, or splices.