The CER0828B from CTS Electronic Components is a RF Duplexer with Frequency 815 to 875 MHz, Band 1 860 to 875 MHz, Band 2 815 to 830 MHz, Insertion Loss 2.7 dB, Operating temperature -40 to 85 Degree C. Tags: Ceramic, Surface Mount. More details for CER0828B can be seen below.