Having bought their 10G modules many times and these 40G modules are also satisfactory. Really plug and play. The whole connection is quite easy and stable. I have nothing to complain about. My account manager has been explained very clearly. I trust their team very much.

Worked as expected. Great price and our Cisco switch accepted it without issue. In general, I do believe quality comes at a price. But FS assures me of their high product performance. I bought so many without a problem. So I believe it's absolutely possible to get good quality at a reasonable price. FS has become my must-go place for optics needs.

We planned to upgrade the existing 10G to 40G as our business grew. The 40G was deployed in our data center, and we wanted it to go to 10G. We sent a draft of our link demand to FS team. They were extremely professional and went above and beyond to resolve my issue. A refined connection diagram was the best reply, and the related transmission rate and explanation were noted alongside each link. According to their design, the whole link was: 40G module #36440 - MTP to 4x LC cables - FHD LC fiber adapters - LC fiber. Finally, we made the order of 40G modules, FHD adapters, MTP breakout cables. The items came in a big box. We plugged the modules on our devices, the LED lights on the devices turned on, and dropped 0 packets.

The 40G modules are recognized by my Juniper switches, no issues. Besides, I also buy MTP cables & horizontal cable manager. It's really a great place that I can buy all things needed.

This module works fine for our Juniper switch and does exactly what it needs to do. Haven't seen any errors so far.

We've been purchasing from fs.com for years, love their reliable products and good prices, best place to go for transceivers and cables. They also have always been professional and helpful.

Going to work on a network re-build project because all traffic routes to our firewall and back down right now (e.g. workstations - firewall - servers). And our old core - distribution - access network is old-fashioned and slow. We decide to change all this by upgrading from 10g to 40g networking in the core layer, we’ve bought our core switches - cisco nexus 93180lc-ex with 24 qsfp+ ports and six qsfp+/qsfp28 uplink ports (the 100g links are used to pass traffic between two cores for redundancy). And the old cisco 10g sfp+ switches with 40g uplinks are moved to the distribution layer. Therefore we need to buy plenty of transceivers and cables. Fs.com is the only place we can think of to supply all these products and ship them immediately, plus they always offer us a very reasonable price.

We contacted our sales rep and she never let me down. The order processing was smooth, when she noticed that there was something added to our quote, that we wouldn't need, she notified me right away and we removed the item, saving us even more money than we anticipated. Everything went as expected. Received all of my items in a timely manner. We ran full testing on some of the transceivers to make sure there were no compatibility or performance issues, all passed the tests without any issues. Now we have finished installing the transceivers and cables, all work perfectly in our new network. Thanks for saving us a great amount of money without performance sacrifice. Will definitely buy from here again!

I tried another vendor's product in a Nexus switch, but they didn't work. I sent these back and ordered 16 transceivers from FS.COM, which worked fine and were not expensive. This makes me very satisfied.

Needed a couple of these for connecting our Cisco switches and extending network with a downlink between two other switches. No compatibility problems so far, and no packet errors or interface issues. The sales told us that they would do the compatibility testing before delivery, really appreciate this.

Properly packaged, and arrived on time. Bought this for our Cisco switches. My old transceiver from other vendors couldn’t work. We had checked, and thought that the laser driver inside the modules was broken. So we need new 40G modules. We have bought some fiber cables from FS before, working great. So we came again for modules. Delivery was fast, love this. Thank you, FS.

I purchased two for an 8-port PoE switch so I could use two QSFP+ ports for both uplink and downlink without having to occupy two PoE Ethernet ports. Their work is great, so far I have not found any problems! good stuff!