The T1ZT4 from Sonoma Scientific is a RF & Microwave Isolator with Frequency 1.85 to 1.99 GHz, Average Power 1 W, Average Power Forward 1 W, Insertion Loss 0.4 dB, Isolation 20 dB. Tags: Module with Connectors, Coaxial Isolator. More details for T1ZT4 can be seen below.