OM2 is for standard 50 micron glass. OM4 is a new designation, currently used by TIA, but not yet adopted by ISO, that identifies enhanced 50 micron glass capable of 10 gigabit Ethernet out to 550. The OM2 fiber type of multimode was standardized in 1998. It still uses LEDs as its light source, but its core, when compared to OM1, is smaller – 50 µm in diameter. The fiber jacket is the same color as OM1 fiber – orange. Most of the time, OM2 fiber was used for 1G Ethernet interconnection in. Multimode fiber optic cable has a larger core, typically 50 or 62. In ISO/IEC 11801 and EIA/TIA standards four types of Multimode – OM1, OM2. These are fiber optic cable designations that originated in the international ISO/IEC 11801 standard.