The B039NC5S from Knowles is a Band Pass Filter with Frequency 3.7 to 4.2 GHz, Bandwidth 500 MHz, Center Frequency 3.95 GHz, Insertion Loss 2.5 to 2.75 dB, Rejection 40 to 45 MHz. Tags: Surface Mount, Ceramic Filter. More details for B039NC5S can be seen below.