This is a 3500ft LC (male) to LC (male) black duplex outdoor-rated fiber armored patch cable. OS2 is a standard single-mode optical fiber commonly used with wavelengths of 1310nm and 1550nm (9/125 microns), and has a maximum attenuation of 1dB/km. The OS2 standard is defined in ISO/IEC 11801. A duplex cable is a two-strand fiber optic patch cable that works best with transceivers that both transmit and receive. 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.