The Slice 10554 auto-retractable utility knife responds to customer demand for a long blade to cut through thick materials, including triple-walled corrugated. When your cut is finished, the ceramic safety utility knife blade pulls back to keep you safe. Rotate the blade edge quickly and without tools to adjust for right or left-handed use. As with all Slice ceramic blades, the retractable utility knife blade is non-conductive, chemically inert, and never rusts.