The ISS-1550-FCUPC from MKS | Newport is a Fiber Optic Isolator with Insertion Loss 1.3 dB, Isolation 50 dB, Operating Temperature 0 to 70 Degree C, Optical Power 300 mW, Polarization Dependent Loss 0.2 dB. More details for ISS-1550-FCUPC can be seen below.