This is a 1000ft non-terminated yellow indoor fiber patch cable. OS1 is a standard single-mode optical fiber commonly used with wavelengths of 1310nm and 1550nm (size 9/125 microns), and has a maximum attenuation of 1dB/km. The OS1 standard is defined inISO/IEC 11801. This indoor cable is perfect for precise process control, ensuring excellent tensile strength and environmental performance that can be constructed without switching off the power. Our patch cables are 100% compliant for all of your networking needs. Our products are guaranteed by federal law to not affect or void OEM warranties.