Uniqcli

Best 1000BASE-SX SFP Transceivers for Multimode Fiber

MSA-compliant 1000BASE-SX modules coded for the switch you already own — with the fiber grade, reach and DOM notes on each card, and live pricing and stock.

1000BASE-SX SFP modules in stock at Uniqcli

How to choose →

A curated selection with live pricing — in-stock lines first, then back-ordered lines with a typical lead time. Every line is sourced through authorized distribution and screened for TAA country-of-origin and NDAA §889 status before checkout.

Juniper-coded pick

StarTech.com

StarTech Juniper RX-550M-SFP Compatible SFP Module

RX550MSFPST

StarTech's Juniper RX-550M-SFP compatible module: 850 nm multimode, LC connector, a listed 550 m reach and DOM support, described by the manufacturer as hot-swappable and MSA compliant. The listing states a lifetime warranty.

Coded for Juniper platforms — name the exact switch model at both ends before you order.

$9.46In stock
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Cisco-coded pick

Lantronix

Lantronix TN-GLC-SX-MM Cisco SFP (mini-GBIC) Module

TN-GLC-SX-MM

Lantronix builds this one against the Cisco GLC-SX-MM: multi-mode optical fiber, a single LC 1000BASE-SX port and a listed 0.55 km maximum distance. The manufacturer's listing records it as TAA compliant.

$22.89In stock
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Dell-coded pick

NSI Industries

ENET Dell Compatible 320-2881 TAA Compliant Functionally Identical…

320-2881-ENC

ENET's Dell 320-2881 equivalent — 850 nm, duplex LC, described in the listing as functionally identical to the OEM part and programmed, tested and supported in the USA, with TAA compliance and a lifetime warranty recorded on the listing.

$30.15In stock
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Force10 pick

NSI Industries

ENET Dell/Force 10 Compatible GP-SFP2-1S TAA Compliant Functionally…

GP-SFP2-1S-ENC

The same ENET build coded for Dell / Force10 GP-SFP2-1S instead: 850 nm duplex LC, functionally identical per the listing, TAA compliant on the manufacturer's record. Worth knowing about if a mixed Dell estate has both platform lines in it.

$30.15In stock
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Finisar-coded pick

AddOn

AddOn Finisar FTLF8519P2BNL Compatible TAA Compliant 1000Base-SX SFP…

FTLF8519P2BNL-AO

AddOn's equivalent of the Finisar FTLF8519P2BNL — multimode, 850 nm, 550 m, LC — for the switches and appliances that were shipped with a Finisar-branded optic rather than a vendor-coded one. The listing records it as TAA compliant.

$28.28In stock
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Fibre Channel pick

Axiom Memory Solutions

Axiom 1000BASE-SX & 1/2-Gbps FC Shortwave SFP Transceiver

SFP2GISXFIN-AX

Axiom's shortwave SFP covers 1000BASE-SX and 1/2-Gbps Fibre Channel on the same part, which is what a storage fabric with mixed Ethernet and FC shortwave links needs. The listing describes it as 100% MSA compatible.

$22.62In stock
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More transceiver modules in the Uniqcli catalog

See all 19,297 transceiver modules

More from across this category. In-stock lines lead, and a back-ordered line carries the same estimated availability its product page does — with live pricing throughout and the same TAA country-of-origin and NDAA §889 screening before checkout.

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Or send it through the quote desk

A 1000BASE-SX module is the short-reach gigabit optic: an 850 nm transmitter over multimode fiber, terminated LC, for links inside a building or across a campus riser. Buyers almost never arrive at this page undecided about the standard — they arrive knowing the switch has empty SFP cages, knowing the fiber in the wall is orange or aqua rather than yellow, and needing the part number that will come up when it is seated. Three things decide that part number, and none of them is the brand on the module.

The first is coding. An SFP carries a small identity EEPROM, and most switch platforms check it before bringing the link up, so a module has to be programmed for the platform it is going into — a module coded for one vendor's switch may simply not be accepted by another's, and some vendors need different coding across their own product families. Everything below is a third-party module built to the MSA specification and coded for a named platform; the compatibility statement belongs to the module's manufacturer and is quoted from the listing, not asserted by us. The second is reach against fiber grade: 550 m is the figure the standard is written around, and it assumes OM2-class fiber, so an OM1 riser will fall short of it and an OM3 or OM4 run has margin to spare. The third is whether you need digital optical monitoring, which is what lets a switch report transmit and receive power per port instead of just up or down.

One thing to weigh before the price: a third-party optic is a genuinely equivalent part, but it is not an OEM part, and some vendors will ask you to reproduce a fault on OEM optics before they take a support case. On an access-layer link that is usually an acceptable trade for the difference in line cost. On a link inside an active support contract for a core platform, it is worth a conversation first. We say that plainly rather than after you have ordered. The selection below is drawn from the 1000BASE-SX modules Uniqcli currently carries, with live pricing and stock status on each card.

Buyer's checklist

How to choose a 1000BASE-SX SFP

  • Name the exact switch, router or NIC model at BOTH ends of the link first — coding is per-platform and sometimes per-family, and it is the single most common reason a module seats but never links.
  • Confirm the fiber is multimode. 1000BASE-SX is an 850 nm multimode standard; a single-mode run needs 1000BASE-LX instead, and the two are not interchangeable at either end.
  • Read the listed reach against the fiber grade you actually have — the 550 m headline figure assumes OM2-class fiber, OM1 falls well short of it, and OM3/OM4 leave margin.
  • Check the connector: LC duplex is standard on SFP, but older GBIC-form parts in the same standard use SC and will not fit an SFP cage.
  • Specify DOM/DDM support if your monitoring platform reads per-port optical power — it costs nothing extra on most modules and is impossible to retrofit.
  • Match the module at both ends. Two different vendors' coded modules will interoperate over the fiber, but each one still has to be accepted by the switch it sits in.
  • Buy one or two spares per closet. A failed optic takes down one link, and a same-day swap is only possible if the spare is already on the shelf.

Coding is the part that decides whether it works

Every SFP carries a small serial EEPROM identifying its vendor, part number and capabilities, and most enterprise switch platforms read it before enabling the port. That check is the whole reason third-party optics are programmed rather than merely manufactured: the module has to answer the question the switch asks. A module coded for one vendor's platform will frequently be refused by another vendor's, and several vendors need different coding across their own product families, so the useful input at quote time is the exact model at each end of the link rather than the brand.

This is also why a module's compatibility statement belongs to the module's manufacturer. The listings below name the OEM part they are built to replace — a Juniper RX-550M-SFP, a Cisco GLC-SX-MM, a Dell 320-2881 — and that naming is the manufacturer's own, quoted here rather than certified by us. What we do before the quote is check the coding against the platform you tell us about, so the question is settled on paper instead of in a wiring closet.

Reach, fiber grade and the 550-metre number

The 550 m figure printed on nearly every 1000BASE-SX module is a specification maximum, not a promise about your building. It assumes 50/125 µm multimode fiber of roughly OM2 quality. Older OM1 62.5/125 plant — very common in buildings cabled before the mid-2000s — carries 1000BASE-SX considerably less far, and long OM1 risers are where this standard quietly fails. OM3 and OM4, by contrast, leave real margin at gigabit and are the grades worth pulling if the plant is being replaced anyway.

Two practical consequences. If the run is longer than a couple of hundred metres and you do not know the fiber grade, find out before ordering rather than after; the jacket colour and the printed legend on the cable usually say. And if the run leaves the building at all, stop and check whether it is single-mode, because a campus or building-to-building link is almost always single-mode plant and needs 1000BASE-LX at both ends instead.

Where optics sit in a switch refresh

Optics are rarely bought alone. They arrive as part of an access-layer refresh that also carries the switches, the controller or management licensing that goes with them, the fiber patch cords and cassettes between the module and the plant, and the labour to stage, configure and install the lot. Treating the optics as a separate line item is how a project ends up with the right modules, the wrong patch polarity and no licence for the management platform on cutover night.

Uniqcli quotes the whole shape of that project through authorized distribution — hardware, the software licences and subscriptions attached to it, and the deployment and lifecycle services around it — rather than only the parts that fit in a cart. For a closet-by-closet rollout, send the switch models and the link list and we will price the optics against the platforms rather than against a category.

Related reading

Keep exploring

Optical transceivers & DACFiber patch cablesSingle-mode vs multimode fiberOM3 vs OM4 fiberNetwork switches catalog hubTAA & §889 screening

FAQ

Common questions

Will a third-party 1000BASE-SX module work in my switch?
It will if it is coded for that platform. Every SFP carries an identity EEPROM, and most enterprise switches read it before enabling the port, so third-party modules are programmed to answer that check for a named platform. The modules here each state the OEM part they are built against — a Juniper, Cisco, Dell or Finisar part number — and that statement is the module manufacturer's own. Give us the exact switch, router or NIC model at each end of the link and the coding question is settled before anything ships. Note separately that some vendors ask for a fault to be reproduced on OEM optics before opening a support case, which is worth weighing on a link covered by an active support contract.
What is the difference between 1000BASE-SX and 1000BASE-LX?
Wavelength and fiber type, which together decide reach. SX transmits at 850 nm over multimode fiber and is specified to roughly 550 m on OM2-class plant; LX transmits at 1310 nm and runs over single-mode fiber out to about 10 km, with limited multimode support via a conditioning patch cord. They are not interchangeable — the fiber already in your building decides which one you can buy. Multimode jackets are usually orange or aqua and single-mode is typically yellow, but the printed legend on the cable is the reliable check.
How far will 1000BASE-SX actually run?
The 550 m headline assumes 50/125 µm multimode of roughly OM2 quality. On older OM1 62.5/125 plant — common in buildings cabled before the mid-2000s — the usable distance is considerably shorter, and a long OM1 riser is the classic place this standard disappoints. OM3 and OM4 leave real margin at gigabit. If the run is more than a couple of hundred metres and the fiber grade is unknown, check the cable legend before ordering rather than after.
Do I need DOM or DDM support?
You need it if your monitoring platform reads per-port optical power, and you cannot add it later. Digital optical monitoring lets the switch report transmit and receive levels for each module rather than only link up or link down, which turns a slowly degrading fiber run or a dirty connector into something you can see coming instead of an outage you diagnose afterwards. It carries little or no price premium on most current modules, so on any link you intend to monitor it is worth specifying up front.
Can Uniqcli quote optical transceivers for a government or education order?
Every line Uniqcli quotes is sourced through authorized distribution and screened for TAA country-of-origin and NDAA §889 status before checkout — with documentation tied to the specific part number, not a product family.
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