OM4 was developed specifically for VSCEL laser transmission and allows 10 Gigabits/second link distances of up to 550 Meters (compared to 300 Meters with OM3). The effective modal bandwidth for OM4 is more than double that of OM3 (4700 MHz. In the complex landscape of fiber optic infrastructure, selecting the right cable type—single-mode (OS1/OS2) or multimode (OM1/OM2/OM3/OM4/OM5)—can define a network's speed, reach, and cost-effectiveness. This guide dissects their technical nuances, evolution, and real-world applications. OM4 fiber is a high-performance multimode optical fiber designed for fast data transmission in applications like data centers and local area networks. However, it can also be used for 25G Ethernet connections up to 70 meters long and 40G/100G Ethernet connections up to 100 meters long.