The AM2100D121 from Anatech Electronics is a RF Duplexer with Frequency 1920 to 1980 MHz / 2110 to 2170 MHz, Band 1 1920 to 1980 MHz, Band 2 2110 to 2170 MHz, Power 5 W, Insertion Loss 1.3 dB. Tags: Surface Mount, Ceramic. More details for AM2100D121 can be seen below.