This worked out of the box on a Mikrotik CRS device, which is a welcome change after trying other low-powered RJ45 transceivers. And yes, it is much cooler than Mikrotik's own S+RJ10. I ordered immediately a few more to complete the move to low-power :)

The 100m version does 10Gb even over the 50 feet of CAT5e that I tried.

Hope you had a great weekend. I have received the package and put some of the optical transceivers to use. The 400G modules are working as expected and we don’t have any issues at the moment. We are very happy with the quality of your product.

I ordered my goods through your website and one day later they are already delivered. So you delivered the goods from your German warehouse to a Belgian location in one day … and that’s without asking for a faster delivery. That’s amazing these days. You guys know what you’re doing. I'm gonna change de initials of FS into Fast Service.

I have used this module to connect 2 x TP-Link switches over 70m of cat 6 cable at 10gb; they stay at 44 degrees C according to DDM data.
Outstanding!

I just received the shipment, and the transceiver modules worked right out of the box.
Thanks for good service and fast handling.