EK Success Cutter Bee 4-Piece Retractable-Knife Value Pack 4-piece set provides retractable knife with precision blade 5-blade cartridge offers safe, hands-free blade replacement 13-inch vinyl self-healing cutting mat with 1/4-inch gridlines 12-inch non-slip metal ruler enables accurate measurements Measures approximately 15 by 14-3/5 by 3 inches