The AD3688-3738D267 from Anatech Electronics is a RF Duplexer with Frequency 3.677 to 3.699 MHz / 3.727 to 3.749 MHz, Band 1 3.677 to 3.699 MHz, Band 2 3.727 to 3.749 MHz, Insertion Loss 3.5 dB, Isolation 110 dB. Tags: Module with Connectors. More details for AD3688-3738D267 can be seen below.