The RADI-3.55-4.25-Cryo-77°K-S23-0.05WR-b from Raditek is a RF & Microwave Isolator with Frequency 3.55 to 5.2 GHz, Average Power Forward 0.5 W, Average Power Reverse 0.5 W, Insertion Loss 0.2 dB, Isolation 22 dB. Tags: Coaxial Isolator. More details for RADI-3.55-4.25-Cryo-77°K-S23-0.05WR-b can be seen below.