The T3743/DA from Smiths Interconnect is a RF & Microwave Isolator with Frequency 3.7 to 4.3 GHz, Average Power Forward 20 W, Average Power Reverse 0.5 W, Peak Power Forward 0.05 kW, Insertion Loss 0.6 dB. Tags: Drop-In, Drop-In Isolator. More details for T3743/DA can be seen below.