The AM1840B1027 from Anatech Electronics is a Band Pass Filter with Frequency 1.81 to 1.88 GHz, Bandwidth 70 MHz, Center Frequency 1840 MHz, Insertion Loss 2 dB, Upper Rejection 30 dB @ 2050 MHz. Tags: Ceramic, Surface Mount, Ceramic Filter. More details for AM1840B1027 can be seen below.