MFJ Enterprises Original MFJ-915 RF Isolator 1.8-30 MHz, 1500W PEP, SO-239 * Eliminate Stray RF from Amateur & CB Radio Antenna Feedlines. * Helps Reduce Interference & TVI. * For 1.8-30Mhz HF uses. * 1:1 , 50 Ohms; Accepts Coax cables with PL-259 Connectors.