The B111NC4S from Knowles is a Band Pass Filter with Frequency 10.25 to 12.75 GHz, Bandwidth 2500 MHz, Center Frequency 11.4 GHz, Insertion Loss 2 to 2.25 dB, Rejection 40 to 40 dB. Tags: Surface Mount, Ceramic Filter. More details for B111NC4S can be seen below.