The R04-M1745-01 from SRTechnology Corporate is a RF Duplexer with Frequency 1.745 to 1.86 GHz, Band 1 1.745 to 1.765 GHz, Band 2 1.84 to 1.860 GHz, Insertion Loss 0.8 dB, Isolation 70 dB. Tags: Module with Connectors. More details for R04-M1745-01 can be seen below.