Sold as a pack of 6.Olfa Replacement Blade - RB18-2 - 18mmSpecification18mm Blade Size0.30mm Blade Thickness2 Rotary Cutter Blade in a plastic case.Olfa RB45 blade is made of special high quality tool steel, it retains a maximum sharp edgeFits any OLFA 18mm rotary cutters, models RTY-4, CMP-3, PRC-2Excellent For:Cutting multiple layers of fabric at once saving you precious time. Perfect ..