The HPII-1310-D from OF-Link Communications is a Fiber Optic Isolator with Insertion Loss 0.4 to 0.6 dB, Isolation 48 dB, Operating Temperature -5 to 50 Degree C, Optical Power 1, 3, 5, 6, 10, 15, 20 W, Polarization Dependent Loss 0.05 dB. More details for HPII-1310-D can be seen below.