All of our standard and custom build singlemode fiber cables feature Corning glass and ceramic ferrules in the connectors for a reliable connection every time. Choose from standard yellow single mode or one of our custom color offerings and the lengths your project requires. All singlemode cables are fully tested for attenuation in accordance with the EIA/TIA-455-171A standard. Attenuation ranges from 0.25 dB/km at 1310 nm to 0.35 dB/km at 1550 nm. Most singlemode cables receive a polish for UPC (Ultra Physical Contact) as indicated by the blue coloGreen connectors. You can always tell APC (Angle Physical Contact) connectors since they are green in color.