The OLISO-P-S106-S155 from Opto-Link is a Fiber Optic Isolator with Insertion Loss 0.4 to 0.55 dB, Isolation 32 dB, Operating Temperature 5 to 70 Degree C, Optical Power 300 (1000mW is also Available) mW, Return Loss 55/50 dB. More details for OLISO-P-S106-S155 can be seen below.