25G SFP28 SFP+ Transceiver, 25GBase-SR Module, 850nm MMF, up to 100-Meter, Compatible with Cisco SFP-25G-SR-S, Ubiquiti, MikroTik, Supermicro, and Open Switches

Works without any fuss with my QNAP 25Gb switches / NICs (I believe these are rebranded Mellanox units, or at least using Mellanox chips). I have been purchasing 10Gtek optics and DACS for some time, in 1G/10G and 25G variants and they have always been excellent. I would recommend them to anyone.

Good quality, packing, and timelines.

Got one of these in a Mellanox ConnectX-4-Lx card and it won't negotiate down to 10Gb talking to a 10gb 10Gtek module in my TP-Link 3008 - don't know why as it's supposed to be able to. Updated the card with the latest firmware (in case that was the issue) and still no joy. Gave it 3 stars as I will keep the module and when I upgrade the switch to 25Gbe I will try again then and my other 10Gtek modules have worked flawlessly so maybe it's user error?

Beware before purchase! Initially I ordered 2 and they seem to work fine until I start to notice performance issues. It took me some time to trace the issue down to an incompatibility between these transceivers and Ubiquiti switches. I ordered 4 more which all show the same major performance issues (down to ~ 30 Mbps under some circumstances. I have tried several other brands including Ubiquiti transceivers and they all work fine. None of these 10GTek work without a problem. I mailed support via their website, They boast good technical support but I never got a reply. I can return 4, but the first order I can no longer return and there is no support. Think twice! Pay a little more.

Fait tres bien le boulot, faut juste faire attention, il n'est pas multi vitesse: certains modules sont compatibles 10Gb et 25Gb, celui la est uniquement compatible 25Gb.

Leider funktionieren diese SFP28 Module nicht wenn in 2 Ubiquiti Switchen die 10Gtek Module verbaut sind. 1x Original Ubiquiti SFP28 Modul und 1x 10Gtek funktionieren hingegen. In diversen Ubiquiti Switchen getestet immer mit gleichem Ergebniss.

They just works!