It was my first time shopping at FS.COM but the experience was good. Several online shops claimed that they had 400G modules but I needed to wait for a long time. Luckily I found FS had Arista compatible XDR4 in stock. I didn’t wait for long before I got them. Quality and compatibility were both OK. Thanks, FS.

These are brilliant. I chose FS due to the higher rating of the manufacturer. I am using them for a 400G-400G direct connection between two buildings. So far, they have performed as hoped. Also, the seller is very keen to provide quality customer service, so I am sure I will buy from FS again should the need arise.

These 400G modules are good choices. Such high-speed optical components using PAM4 modulation can be really perfect. I have to say, the whole data transfer is running beyond our expectations. There is nothing wrong with them.

I have bought six 400G modules for running in a business data center. We never had a single problem. They have worked flawlessly in my Juniper switches. 400Gb transmission without issue over my 1km cabling. Their modules always work as described. It's even good for 400G products. A reliable vendor to partner with.

Bought for our datacenter and worked well. Initially bought one of the units and it worked seamlessly. Then bought the second one. These have good compatibility with our temporary devices. Installing and configuring are all easy.

The models came brand new, wrapped nicely, no damage. Had no issues whatsoever. Using them successfully in our switches. Just a few seconds later, switches were linked and started transferring data over SMF. Overall, I'm very pleased with the purchase.