Satisfied with the high quality and superior construction of these modules. They connected to QSFP28 ports easily and firmly. They were reasonably priced and worked great. Have had no problems since we put them into use. Saved us a bunch of money!

Got the single lambda transceivers and some other 100GBASE-ER4L and 112GBASE-OTU4 QSFP28 Dual Rate and 100GBASE-LR4 and 112GBASE-OTU4 QSFP28 Dual Rate optical transceivers. They are all working on the 1310nm wavelength other than 1550nm which is told to be susceptible to dispersion. They worked well indeed.

I have nothing to complain about. Product was delivered on time with so well-sealed package even if I only bought two of them. Would choose FS again if I have future needs.

This is exactly what I want. I bought some QSFP28 single lambda modules and the matched LC fiber cables. I’ve run them on 100Gbps. They are all in good condition. No compatibility problems or traffic errors on my switches.

We’ve purchased 100GBASE-LR QSFP28 single lambda 1310nm 10km transceiver (PAM4 modulation) and 100GBASE-LR4 QSFP28 1310nm 10km transceivers (NRZ modulation). Both I hot installed the latter on Juniper MX10003 and it took a few sec before the switch recognized them. I'll be finishing up the 5G project soon so I'll get the single lambda one tested and will update if I spot any issues.

The first time to try the single lambda transceiver, find FS without hesitant. If you run into problems, FS gives support, of course; but some supplier I contacted, does not.