The AM1800D311 from Anatech Electronics is a RF Duplexer with Frequency 1750 to 1780 MHz / 1840 to 1870 MHz, Band 1 1750 to 1780 MHz, Band 2 1840 to 1870 MHz, Power 2 W, Insertion Loss 2.8 to 3 dB. Tags: Surface Mount. More details for AM1800D311 can be seen below.