The PSFI-06-A-B-C-D-E from HJ Optronics, Inc. is a Fiber Optic Isolator with Optical Power 300 mW, Isolation 30 to 45 dB, Insertion Loss 1.6 to 3.4 dB, Wavelength 1064 nm, Polarization Dependent Loss 20 dB. More details for PSFI-06-A-B-C-D-E can be seen below.