Originally this type of panel holder was developed in the late 1920's for holding aircraft skin in place for riveting. Today coach builders and NASCAR body men use them daily. These are great for holding panels in place for fitting or welding. To use, just drill a hold (to fit holder size) through both the underlying original panel and the overlapping replacement panels and insert the holder. Each holder has 25lbs of holding pressure. The side grip clamps are great for grabbing the edge of panels. The Drill Stop helps you from breaking drill bits and bending panels when the chuck hits the panel. These are reusable and last for many, many jobs. Cleco System came from the Aerospace industry.
Safety First - Always wear adequate & proper EYE, EAR, FACE, BODY and RESPIRATORY PROTECTION.