There are a few solar panel alignment tools out there but they all seemed overkill or fragile. This is a lightweight tool to help you maximize the output of your portable solar panels. I was surprised to find out that a misaligned panel can sap 20-50% of your power output… it really needs to be rotated and tilted to directly point at the sun to get max output. The clip portion is 4mm which seemed about right to fit on some portion of the edge of all my folding portable solar panels but you may need to scale to fit yours using the formula Scale % = [desired size in mm] * 25. To use, clip the print on the edge so that it's sticking straight out (orthogonal) from the panel and then tilt/rotate your panel so that the light coming through the hole shines directly on the divot. The photo is shown purposely misaligned to illustrate the idea. For maximum visibility, paint the divot using a paint marker or similar.