The CER0023A from CTS Electronic Components is a RF Duplexer with Frequency 1.85 to 1.99 GHz, Band 1 1.93 to 1.99 GHz, Band 2 1.85 to 1.91 GHz, Power 2 to 20 W, Insertion Loss 3.7 to 4 dB. Tags: Ceramic, Surface Mount. More details for CER0023A can be seen below.