The CIR-4-15-L-1-2 from AFW Technologies is a Fiber Optic Circulator with Insertion Loss 0.8 dB, Isolation 45 dB, Operating Temperature -5 to 50 Degree C, Optical Power 300 mW, Polarization Dependent Loss 0.15 dB. More details for CIR-4-15-L-1-2 can be seen below.