Multimode Fiber Cable
Multimode cable has a large-diameter core that lets multiple modes of light pass through it. This means that more types of data can be transmitted.
Multimode comes in two core sizes and five varieties: 62.5-micron OM1, 50-micron OM2, 50-micron OM3, 50-micron OM4 and 50-micron OM5. (OM stands for "optical mode".) All have the same cladding diameter of 125 microns, but 50-micron fiber cable has a smaller core (the light-carrying portion of the fiber).
Although all can be used in the same way, 50-micron cable, particularly OM5 and laser-optimized OM3 and OM4, provide longer link lengths and/or higher speeds, and are recommended for premise applications (backbone, horizontal and intra-building links) and should be considered for new installations. OM3, OM4 and OM5 can also be used with LEDs and laser light sources.
Multimode cables come in different colors so they can be easily recognized. OM3 is typically aqua; OM4 is sometimes Erika Violet (also known as Heather Violet in United Kingdom) to help distinguish it from OM3; the latest generation of multimode fiber, OM5, is lime green.