In this guide, we rank the Top 5 Global SX SFP module manufacturers & Suppliers of SX SFP modules based on compatibility, reliability, and market reputation.
The 1000BASE-SX SFP is the workhorse of the networking world. Whether you are connecting switches in a data center or linking floors in an office building, this 850nm Multimode module is likely the most common component in your inventory.
But when it comes to buying them, IT managers face a dilemma:
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Do you pay $500+ for a branded Cisco module?
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Do you trust a $7 generic module from a random online seller?
At the end, we will also reveal a “Factory Direct” secret that allows you to get Tier-1 quality without the brand-name markup.
What is an “SX” SFP Module? (The Specs)
Before we look at the suppliers, let’s define the standard to ensure you are buying the right part.
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Standard: IEEE 802.3z 1000BASE-SX
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Wavelength: 850nm (Short Wavelength)
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Cable Type: Multimode Fiber (OM3/OM4 recommended)
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Standard Distance: 550 meters (on OM3) / 275 meters (on OM1)
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Connector: Duplex LC
Factory Insider Note: The “2km” Myth You might see some vendors selling “SX 2km” modules. Be careful. Standard 850nm physics limits transmission to ~550m. Most “2km” multimode modules actually use a 1310nm wavelength (technically 1000BASE-SX2 or proprietary tech).
If you need <550m: Buy Standard SX (850nm). It’s cheaper.
If you need >550m on Multimode: Ask us for the special “2km Extended” version specifically.
The Top 5 SX SFP Suppliers (2026 Edition)
1. Cisco Systems (The Gold Standard)
Part Number: GLC-SX-MMD
Best For: Government & Financial Enterprise.
Overview: Cisco is the reference standard. Their modules are famous for rigorous testing and high reliability. If your network budget is unlimited and you require 100% “Cisco TAC” support compliance, you buy genuine Cisco.
The Downside: Price. You are paying heavily for the logo. A single genuine SX module can cost 10x-50x more than a compatible one.
2. Finisar (Coherent Corp.)
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Part Number:
FTLF8519P3BNL -
Best For: OEMs & Engineers.
Overview: Here is an industry secret: Cisco doesn’t make their own lasers. Companies like Finisar (now Coherent) do. Finisar is the largest optical component manufacturer in the world. Their SX modules are the definition of “Reference Quality.”
The Downside: They typically sell in massive volumes to other manufacturers. Buying small quantities as an end-user can be difficult or expensive through distributors like DigiKey.
3. FS.com (Fiberstore)
Best For: SMBs & E-commerce Buyers.
Overview: FS.com disrupted the market by making optics accessible online. They offer good quality compatible modules for standard switches (Ubiquiti, Netgear, etc.) with fast shipping from warehouses in the US and Europe.
The Downside: Fixed Coding. While good for standard gear, their modules often struggle with complex, proprietary coding requirements for high-end legacy platforms unless you buy their specific “Custom” box.
4. StarTech.com
Best For: IT Departments & General Contractors.
Overview: You will find StarTech on CDW and Amazon. They are known for their “Lifetime Warranty” and excellent retail packaging. They are a safe choice for IT admins who need to buy just 2-3 modules for a quick replacement.
The Downside: Retail Pricing. While cheaper than Cisco, they are still significantly more expensive than buying direct from a specialist factory.
5. 10Gtek
Best For: Home Labs & Low-Cost Projects.
Overview: A popular budget choice on Amazon. 10Gtek offers functional SX modules for basic networking needs. They are great for connecting a home server or a non-critical switch.
The Downside: Quality Control. For mission-critical enterprise links, consistency can vary compared to Tier-1 manufacturers.
The “Factory Direct” Alternative: Why Pay for the Label?
The suppliers above are excellent, but they all share one trait: You are paying for their marketing, warehousing, and brand premium.
What if you could buy the same industrial-grade SX module, with the same Macom/Maxim chips, directly from the production line?
Comparison: Which Supplier Fits Your Business?
| Feature | Tier-1 Brands (Cisco/Finisar) |
Online Retailers (FS/Amazon) |
Wolontek (Factory Direct) |
|---|---|---|---|
| Cost Basis | High ($$$) (Huge Brand Premium) |
Medium ($$) (Retail Markup) |
Factory Price ($) (No Middlemen, Save 30%+) |
| Compatibility | Locked (Only works on their hardware) |
Standard / Fixed (Hard to customize) |
✔ Fully Custom (We code for ANY brand/firmware) |
| Private Labeling | ✘ No (Must sell their brand) |
✘ No (Usually their logo) |
✔ Yes (OEM/ODM) (Your Logo, P/N, & Packaging) |
| ⚙️ Testing Standard | Industrial (Tier-1 Standard) |
Commercial (Varies by batch) |
✔ Industrial (100% Tested) (Eye Diagram & Temp Cycle) |
| Ideal Buyer | Banks, Gov, Enterprises | Home Users, Labs, Urgent Needs | Distributors, ISPs, Project Integrators |
| Support | Slow / Via Partner | Ticket System | ✔ Direct Engineer Access (Fast Technical Response) |
The Bottom Line: Which Supplier is Right for You?
- Buying for a Compliance-Heavy Bank? → Stick with Cisco/Juniper.
- Need just 1 unit for a home lab? → Buy from Amazon/FS.
- Building Your Own Brand or need 100+ units? → Partner with Wolontek for factory-direct pricing and full OEM support.
Meet Wolontek: Your OEM Manufacturing Partner
At Wolontek, we are not a retailer; we are a Manufacturer based in China’s Optical Valley. We produce optical transceivers for many of the “brands” you see in the market today.
Why Source SX SFPs from Wolontek?
1. The “Universal” Code (Compatibility)
Unlike retailers who sell “fixed” modules, our engineers can flash the EEPROM of our SX modules to match any environment.
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Need it to look like HPE Aruba? We code it.
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Need it to work in a Juniper EX switch? We code it.
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Need a Dual-Code that works in both? We can do that too.
2. Industrial-Grade Components
We don’t use “binned” or recycled lasers. Our SX modules use top-tier VCSEL lasers that guarantee:
Wide Temperature Range: -40°C to +85°C (Industrial) options available.
Clean Eye Diagrams: Ensuring zero packet loss even at full 550m distance.
3. Factory Direct Pricing (The 60% Savings)
By cutting out the distributor, the importer, and the retailer, our price for a high-performance SX SFP is a fraction of the market rate.
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MOQ: Flexible. Whether you need 50 units for a project or 5,000 for stock.
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Private Labeling: We can print YOUR Logo and YOUR Part Number on the label, helping you build your own brand assets.
Ready to Cut Your Optical BOM Costs by 30%?
Stop paying the “Brand Tax” on 1000BASE-SX Modules. Partner directly with Wolontek to get Tier-1 performance, fully custom coding, and your own private label—at factory prices.
⚡ Fast Response: Our engineers typically reply within 12 hours.