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 meters. OS1 applies to standard singlemode glass while OS2 refers to a higher performing, low-water peak singlemode glass. While they developed the. This article explains the core differences between OS1 and OS2 singlemode fibers, as well as OM3, OM4, and OM5 multimode fibers—to help OEM clients, installers, and data center engineers make informed decisions. Instead of a traditional interlocking armor, it utilizes a stainless steel coil technology. This allows for the cable. Protect your data connections and network installations with our indoor/outdoor tight buffered armored fiber cable. OM1 Multimode fiber type was the first MMF version to be standardized in 1989.