Make long, uniform bends and folds in sheet metal with these bar folders. They have two notches, one on each side of the bar, that act as depth gauges to ensure an even fold. The notches have different depths, so you can choose the fold size that suits your application. Use the sight holes on the tool to make sure your material is properly aligned before bending. These tools are commonly used in HVAC, roofing, and siding applications.