The BP0805A3900ASTR from KYOCERA AVX is a Band Pass Filter with Frequency 3.6 to 4.2 GHz, Bandwidth 600 MHz, Center Frequency 3900 MHz, Insertion Loss 2.5 dB, Upper Rejection -25 to -22 dBc. Tags: Surface Mount. More details for BP0805A3900ASTR can be seen below.