The CN-400 series is a high quality instrument with a unique feature which makes tedious measurements of SWR and power during antenna tests, matching and tuning of transmitters a breeze. SWR and power indicators are installed in one meter unit. One scale will indicate Forward Power, another scale Reflected Power and SWR is indicated at the crossing point of the 2 needles. This unique feature makes it possible to read Forward Power. Reflected Power and SWR all at the same time. "Without M” type meters have not meter scale illumination lamp and mounting hardware is an option.