The CER0223A from CTS Electronic Components is a RF Duplexer with Frequency 890 to 960 MHz, Band 1 935 to 960 MHz, Band 2 890 to 915 MHz, Insertion Loss 3.5 dB, Operating temperature -30 to 85 Degree C. Tags: Ceramic, Surface Mount. More details for CER0223A can be seen below.