This is a MSA compliant 3m angled MPO (female) to 2x angled MPO (female) 12-strand yellow OS2 LSZH patch crossover polarity-B 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 low smoke zero halogen cable reduces the amount of toxic and corrosive gas emitted during combustion. This type of material is typically used in poorly ventilated areas such as aircrafts, rail cars or ships and will self-extinguish. Our patch cables are 100% compliant for all of your networking needs and are guaranteed by federal law to not affect or void OEM warranties.