The AD3437-3537D251 from Anatech Electronics is a RF Duplexer with Frequency 3412.5 to 3462.5 MHz / 3512.5 to 3562.5 MHz, Band 1 3412.5 to 3462.5 MHz, Band 2 3512.5 to 3562.5 MHz, Insertion Loss 1 dB, Isolation 40 dB. Tags: Module with Connectors. More details for AD3437-3537D251 can be seen below.