- Cyber Security
DNS Security: Protecting Your Business at the Network Level
19 Feb, 2026

£18.55 inc. VAT
AI-generated summary
For £15.46 ex-VAT, the TP-Link TL-SM311LS is exactly the kind of low-cost “make it work” SFP you buy when you already have the right fibre environment and you just need a reliable link. It’s a sensible choice for small business switches and patch-panel setups where you don’t want to pay enterprise-branded prices for a module doing a fairly boring job: move data reliably on the same wavelength. In day-to-day terms, it’s the sort of part that earns its keep—swap it in, it negotiates, and your link comes back without drama.
That said, I’d only buy it if you’re confident about compatibility: the key things are the fibre wavelength and the switch model’s supported optics/SFP type. If you’re mixing vendors or you’re not sure whether your existing link is truly the same standard, it can become a faff (or worse, you end up buying the wrong optics and losing time). Also, if this is for a mission-critical uplink where downtime is costly, you might prefer a branded or higher-tier module even if it costs more—worth it for peace of mind and sourcing certainty.

STARTECH
StarTech.com HPE 455883-B21 Compatible SFP+ Module, 10GBASE-SR, 10GbE Multi Mode (MMF) Fiber Optic Transceiver, LC 300m, 850nm, DDM, HPE 6120XG, 6120G, Flex Fabric, Mini GBIC Transceiver - Lifetime Warranty (455883B21ST) - SFP+ transceiver module (equivalent to: HP 455883-B21) - 10GbE - 10GBase-SR - LC multi-mode - up to 300 m

STARTECH
StarTech.com HPE J4859C Compatible SFP Module, 1000BASE-LX, 1GbE Single Mode (SMF)/Multi Mode MMF Fiber Optic Transceiver, LC Connector, 10km, 1310nm, DDM, HPE 1400, 1700, 1820, Mini GBIC - Lifetime Warranty (J4859CST) - SFP (mini-GBIC) transceiver module (equivalent to: HP J4859C) - 1GbE - 1000Base-LX - LC - up to 10 km - 1310 nm - for HPE 1700, 2610, 93XX, Switch XL 10/100/1000, HPE Aruba 2530, 2930F 24, 2930F 48, 5406

Lenovo
QLogic 10Gb SFP+ SR Optical Transceiver - SFP+ transceiver module - 10GbE - 10GBase-SR - for Converged HX2310, Storage DX8200, System x3100 M5, x3250 M4, x3250 M6, ThinkSystem SR250

STARTECH
StarTech.com HPE 813874-B21 Compatible SFP+ Module, 10GBASE-T, SFP to RJ45 Cat6/Cat5e, 10GE Gigabit Ethernet SFP+, RJ-45 (Copper) 30m, HPE BladeSystem, c-Class, Mini GBIC SFP+ Transceiver - Lifetime Warranty (813874B21ST) - SFP+ transceiver module (equivalent to: HP 813874-B21) - 10GbE - 10GBase-T - RJ-45 - up to 30 m