Pen blades are made of the highest quality surgical grade stainless steel, retractable pen-like design, easy ruler built in to end of the handle. PenBlade Safety Scalpel’s retractable blade activates like a click pen and retracts with a simple press of a button. The pen-style activation is intuitive, using existing muscle memory. The release button is positioned near the front of the scalpel where it can be pressed without looking or repositioning the hand. The #10 pen blade Cuts through foam board, cardboard, balsa wood, and is ideal for heavy weight materials. Decrease risk of injury by reducing blade exposure It is ideal for use in art, craft and hobby applications. Designed to be standardized across all art and craft applications ergonomic design which makes it more comfortable to hold and operate.