The R438538100 from Radiall is a Low Pass RF Filter with Frequency DC to 15 GHz, Insertion Loss 2 dB, Return Loss 15 to 18 dB, Operating_Temperature -273.14 to 76.85 Degree C (0.01 to 350 K), Storage_Temperature -55 to 125 Degree C. Tags: Connectorized, Cryogenic Filter, Infrared Filter. More details for R438538100 can be seen below.