The CER0554B from CTS Electronic Components is a RF Duplexer with Frequency 1.53 to 1.66 GHz, Band 1 1.53 to 1.56 GHz, Band 2 1.61 to 1.66 GHz, Power 10 W, Insertion Loss 1.3 to 1.4 dB. Tags: Ceramic, Surface Mount. More details for CER0554B can be seen below.