The CER0477B from CTS Electronic Components is a RF Duplexer with Frequency 1.71 to 2.16 GHz, Band 1 2.11 to 2.16 GHz, Band 2 1.71 to 1.76 GHz, Power 2 to 20 W, Insertion Loss 1.5 dB. Tags: Ceramic, Surface Mount. More details for CER0477B can be seen below.