The ATc4-8 from Narda-ATM is a RF & Microwave Circulator with Frequency 4 to 8 GHz, Average Power Forward 2 W, Peak Power 20 W, Insertion Loss 0.35 to 0.4 dB, Isolation 20 to 22 dB. Tags: Coaxial Circulator. More details for ATc4-8 can be seen below.