MFJ-939Y4 Plug & Play 200W 1.8-30MHz HF Autotuner for Select Yaesu HAM Radios Plug & Play! You wont even know its there! MFJ-939Y4 automatically tunes your antenna as you tune your radio. SWR is always low Tunes your coax fed or random wire antennas 1.8-30 MHz from 2 Watts QRP to full 200 Watts SSB/CW Matches 6-1600 Ohms (SWR up to 32:1) -- thats a 50% wider matching range than competing products that are less capable and higher priced . . . and its made in the USA. MFJ has 256 values each of capacitance and inductance for 131,072 matching solutions giving you a finely tuned very low SWR. That`s 4 times the 32,768 solutions of competitors using only 128 L/C values each! As Small as Your Radio! Only 6 1/2W x 2 7/8H x 8 3/8D. Weighs just 2.4 lbs