The I221(Y)T-(Z) - Circulator from Sinclair Technologies is a RF & Microwave Circulator with Frequency 138 to 174 MHz, Bandwidth 5 MHz, Average Power Forward 125 W, Insertion Loss 0.7 to 1 dB, Isolation 50 to 75 dB. Tags: Coaxial Circulator. More details for I221(Y)T-(Z) - Circulator can be seen below.