The B042OD4S from Knowles is a Band Pass Filter with Frequency 3.75 to 4.75 GHz, Bandwidth 1000 MHz, Center Frequency 4.25 GHz, Insertion Loss 3 to 3.5 dB, Rejection 40 to 50 MHz. Tags: Surface Mount, Ceramic Filter. More details for B042OD4S can be seen below.