The Dahle Professional X-Acto knife, with a 9mm blade, is a precision knife with a retractable blade, used for fine and detailed cuts in paper, cardboard, vinyl, and other materials in cutting, model making, and fine arts work. The Professional line is distinguished by a more robust body and a reinforced locking mechanism, designed for intensive professional use in precision cutting work, while maintaining the thin 9mm blade suitable for details. The blade locking system allows you to adjust the exposed length according to the thickness of the material being cut, and to safely retract the blade after use. It is an essential tool on any cutting, bookbinding, or model making workbench.