The C18B2 from Sonoma Scientific is a RF & Microwave Isolator with Frequency 17.5 to 21.5 GHz, Insertion Loss 0.5 dB, Isolation 30 dB, Operating Temperature 0 to 25 Degree C. Tags: Module with Connectors, Coaxial Isolator. More details for C18B2 can be seen below.