The ID3900D from Orion Microwave Inc. is a RF & Microwave Isolator with Frequency 3.5 to 4.3 GHz, Average Power 50 W, Average Power Forward 50 W, Average Power Reverse 20 W, Peak Power Forward 0.5 kW. Tags: Drop-In, Drop-In Isolator. More details for ID3900D can be seen below.