The 991-340420-301 from M2 Global Technology is a RF & Microwave Isolator with Frequency 3.4 to 4.2 GHz, Average Power Forward 20 W, Average Power Reverse 10 W, Insertion Loss 0.4 dB, Isolation 20 dB. Tags: Drop-In, Drop-In Isolator. More details for 991-340420-301 can be seen below.