The AM1997B540 from Anatech Electronics is a Band Pass Filter with Frequency 1.985 to 2.01 GHz, Bandwidth 25 MHz, Center Frequency 1997.5 MHz, Insertion Loss 3.6 dB, Rejection 3 to 70 dB. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for AM1997B540 can be seen below.