The 28-52-02A from TX RX Systems is a RF Duplexer with Frequency 215 to 250 MHz, Band 1 215 to 250 MHz, Power 250 W, Insertion Loss 1.2 dB, Isolation 55 dB (Between Channel) / 90 dB (Per Channel). Tags: Rack Mount. More details for 28-52-02A can be seen below.