They are replacement blades the Tamiya Modeler’s Knife Pro (product 74098).
• Scriber blades x 5
• 0.4 mm thick.
• Pull towards you to ultimately get the subject material.
• enables you to get then break off synthetic dish towards desired size.
• Thinner than Item 74091 Plastic Scriber II.
• Suitable for really precise and detail by detail work.