G.651 Mutimode fiber (OM2) is mainly used in LAN,not suitable for long distance transmission, but in the range of 300 to 500 meters, IEC and GB/T further subdivision parameters according to their core diameter, cladding diameter, numer ical aperture of Ala, Alb, Alc and Ald four sub categories
G.651-0M2-Ala-Al(50/125), 62.5/125-Alb,
OM1 also called multi mode fiber (62.5-125) Gigabit transmission distance is only 275 meters
OM2 is also called G.651 fiber or multimode fiber (50 - 125),and Gigabit transmission distance is 550 meters
OM3 OM3-150 reaches 10000 Mega OM3-300 OM3-550 at a distance of 150 meters
