The TX2C1 from Sonoma Scientific is a RF & Microwave Isolator with Frequency 257 to 277 MHz, Average Power 4.2 kW, Average Power Forward 4.2 kW, Insertion Loss 0.25 dB, Isolation 20 dB. Tags: Module with Connectors, Coaxial Isolator. More details for TX2C1 can be seen below.