The C1BU11 from Sonoma Scientific is a RF & Microwave Isolator with Frequency 1.2 to 1.3 GHz, Average Power 250 W, Average Power Forward 250 W, Insertion Loss 0.5 dB, Isolation 20 dB. Tags: Module with Connectors, Coaxial Isolator. More details for C1BU11 can be seen below.