The CER0546A from CTS Electronic Components is a Band Pass Filter with Frequency 3.95 to 4.05 GHz, Bandwidth 100 MHz, Insertion Loss Less than 2.5 dB, Rejection 41 to 43 dB, Power 2 to 20 W. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for CER0546A can be seen below.