The OISM-20-3-1-3 from AGILTRON is a Fiber Optic Isolator with Insertion Loss 0.45 to 0.50 dB, Isolation 45 dB, Operating Temperature -5 to 70 Degree C, Optical Power 1 W, Polarization Dependent Loss 0.1 dB. More details for OISM-20-3-1-3 can be seen below.