Fibrain FRM family of Faraday mirrors and rotators are passive optical devices utilizing the magneto-optic effect to rotate in a controlled way the polarization plane of the incident light. They are frequently used in systems and devices which require polarization- and/or directional isolation, like tunable lasers, optical amplifiers, interferometers or in various sensing schemes. Fibrain FRM devices are available in versions optimized for different spectral bands, as well as in the polarization maintaining (PM) versions. They can be connectorized with various types of connectors. Fibrain welcomes custom inquires, for example for non-standard spectral working ranges, connector types or packaging.