This Swiss Tech Knife set offers a 18mm and 9mm snap off knife with SK5 steel for extra sharpener for ideal sharpness and durability.This Swiss Tech Knive set is perfect for cutting and allows you to keep your knife sharpest.Prevent blade slipping with the safety lock tab. Always keep your blade fresh and sharp by snapping off the blade for a new sharp cutting tip.Sections snap off easily creating new, sharp blade. Retractable blade with lock. Ergonomic handle for ease of use.Use for commercial or industrial applications like thicker paper, tape, plastic, cardboard, balsa, bass wood, photos, coupons, cardstock, mat board, foam board, delicate fabrics, crafts, , ups or post office packages.