The CU1S1281BC-3700-00 from TDK is a RF & Microwave Circulator with Frequency 3.6 to 3.8 GHz, Bandwidth 200 MHz, Average Power Forward 20 W, Insertion Loss 0.3 dB, Isolation 18 dB. Tags: Surface Mount, Surface Mount Circulator. More details for CU1S1281BC-3700-00 can be seen below.