Best OM4 Multimode Fiber Patch Cables for 40G and 100G Links

A duplex LC cord is the workhorse of a multimode plant: two fibers in one boot, transmit and receive, terminating an SFP+ or SFP28 optic at each end. It is the right cable for the overwhelming majority of 10G and 25G links inside a rack or between adjacent cabinets, and the SC and ST variants stocked here cover the older panels and transceivers a brownfield site still runs. Where density matters, uniboot and microboot designs pack more cords into the same patch field without bending the fiber past its minimum radius.

At 40G and 100G the link stops being a pair. A 40G-SR4 or 100G-SR4 optic transmits across four lanes in each direction, so the cable is an MPO or MTP trunk carrying 12 or 24 strands in a single connector, usually landing on a cassette that breaks the trunk out to LC. The OM4 MPO assemblies here are the backbone piece of that design — order the trunk, the cassettes and the LC jumpers as one bill of materials, because an MPO trunk with no breakout is a connector nothing on the switch can accept.

The jacket is chosen for the pathway, not the port. OFNR riser-rated cable is the default for a vertical run rising between floors; LSZH (low smoke zero halogen) cable is specified where occupied space, air handling or a local code limits the smoke and halogen a burning cable may produce; and an armored assembly adds a metal-interlock or corrugated layer for a run that leaves the protected tray and crosses a floor or a plenum void. Match the rating to what the inspector will check, and standardize it across a site so a substitution never quietly downgrades a run.

Color is a convention worth enforcing even though it carries no rating. OM4 is conventionally aqua, and several manufacturers here use Erika violet specifically so OM4 stands apart from OM3 aqua at a shared patch field — a small thing that prevents a technician from patching a 100G-rated run into a 40G-rated one. Whatever the site standard, keep it consistent, label both ends, and record the grade on the port map rather than trusting the jacket color alone.

A patch cord is rarely the whole job. An OM4 link lands on a transceiver at each end, passes through a cassette or an adapter panel, and is dressed into a fiber enclosure or a raceway sized for its bend radius — and every one of those parts can be quoted on the same line. Where a run crosses a compliance boundary, the same part numbers that carry the OM4 grade are the ones we screen for TAA country-of-origin and NDAA Section 889 status, tied to the exact SKU rather than to a product family, so the acquisition team verifies the cable that ships and not a brand claim.