The CER0397F from CTS Electronic Components is a RF Duplexer with Frequency 1.71 to 1.88 GHz, Band 1 1.81 to 1.88 GHz, Band 2 1.71 to 1.79 GHz, Insertion Loss 3.6 dB, Operating temperature -40 to 85 Degree C. Tags: Ceramic, Surface Mount. More details for CER0397F can be seen below.