The Mayhew 11 pc. Hollow Punch Set is used to create precise gaskets and washers in softer materials, like cloth, vinyl, leather, light sheet metal, and gasket metal. Many sizes, kits, handles, and mandrels are available in the 11 pc. hollow punch set for extensive configurations. The dual cutting heads in the hollow punch set also allow for punching concentric circles in one strike. The hollow punch set has metric measurements.