The AM3437-3537D997 from Anatech Electronics is a RF Duplexer with Frequency 3.43 to 3.45 GHz / 3.53 to 3.55 GHz, Band 1 3425 to 3450 MHz, Band 2 3525 to 3550 MHz, Power 2 W, Insertion Loss 2.7 dB. Tags: Surface Mount, Ceramic. More details for AM3437-3537D997 can be seen below.