The CER0290A from CTS Electronic Components is a RF Duplexer with Frequency 3.43 to 3.55 GHz, Band 1 3.53 to 3.55 GHz, Band 2 3.43 to 3.45 GHz, Insertion Loss 3 dB, Operating temperature -40 to 70 Degree C. Tags: Ceramic, Surface Mount. More details for CER0290A can be seen below.