611373 Prym Replacement Blades for Mini Cutter Blades - Size 28 mm - 2 pieces. The replacement blades are made of high-quality stainless steel and are available in various sizes for all Prym rotary cutters. Safely packaged in a practical plastic container, they should be replaced regularly, as dull blades cause fatigue, inaccurate cutting, and damage to the cutting mat. Be careful when replacing them, as they are extremely sharp.