The CBFU3U41050B from Cernex Inc is a Band Pass Filter with Frequency 397 to 403 MHz, Bandwidth 6 MHz, Insertion Loss 1 dB, Upper Rejection 50 dB at 430MHz, Lower Rejection 60 dB at 370MHz. Tags: Helical Resonator Filter. More details for CBFU3U41050B can be seen below.