This is a 3.5m SC (male) to SC (male) yellow simplex riser-rated mini-boot fiber 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. This optical fiber, nonconductive, riser (OFNR) cable is best suited for use in interior fiber-optic applications. A duplex cable is a two-strand fiber optic patch cable that works best with transceivers that both transmit and receive.