The BP5900B0603AT from Frontier Electronics is a Band Pass Filter with Frequency 4.9 to 5.84 GHz, Insertion Loss 1.7 dB, Rejection 29 to 33 dB, VSWR 2.00:1, Operating_Temperature -40 to 85 Degree C. Tags: Surface Mount, Ceramic Filter. More details for BP5900B0603AT can be seen below.