The B280LB0S from Knowles is a Band Pass Filter with Frequency 27 to 29 GHz, Bandwidth 2 GHz, Center Frequency 28 GHz, Insertion Loss 1.5 to 2 dB, Rejection 30 to 40 dB(Lower, Upper). Tags: Surface Mount, Ceramic, Ceramic Filter. More details for B280LB0S can be seen below.