I made one for a fellow and he likes it. Its just a simple led that lights up when you detect a target and in pinpoint either brightens a little or dims depending upon how close you are to the target. It plugs into your headphone jack and can be mounted where ever is best for the user. Works best with the volume at 75 percent or higher...Hope to have a short sample video to show how it does tomorrow some time... Simple but effective and if you have major hearing problems this will help tremendously. Feel free to email with any questions. $7.50 shipped first class anywhere in the lower 48. Thanks.