The 28-66-04H from TX RX Systems is a RF Duplexer with Frequency 442 to 450 MHz, Band 1 442 to 450 MHz, Power 100 W, Insertion Loss 1.5 dB, Isolation 35 dB (Between Channel), 80 dB (Per Channel). Tags: Rack Mount. More details for 28-66-04H can be seen below.