The CER0017B 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 1.63 to 1.66 GHz, Operating temperature -40 to 85 Degree C. Tags: Ceramic, Surface Mount. More details for CER0017B can be seen below.