The 28-66-02B from TX RX Systems is a RF Duplexer with Frequency 442 to 450 MHz, Band 1 442 to 450 MHz, Power 350 W, Insertion Loss 0.6 dB, Isolation 46 dB (Between Channel), 100 dB (Per Channel). Tags: Rack Mount. More details for 28-66-02B can be seen below.