The 28-70-09A from TX RX Systems is a RF Duplexer with Frequency 450 to 470 MHz, Band 1 450 to 470 MHz, Power 250 W, Insertion Loss 1.25 dB, Isolation 70 dB (Between Channel), 100 dB (Per Channel). Tags: Rack Mount. More details for 28-70-09A can be seen below.