The ATc17-20 from Narda-ATM is a RF & Microwave Circulator with Frequency 17 to 20 GHz, Average Power Forward 2 W, Peak Power 50 W, Insertion Loss 0.3 to 0.4 dB, Isolation 22 to 24 dB. Tags: Coaxial Circulator. More details for ATc17-20 can be seen below.