Safe Scrape™ double-edged Delrin® plastic blades. Sold ina 10 blade blister pack – total of 6 packs. Blister carded for retail sales. Orange blades – 20 edges! Why use plastic blades? Because they will not scratch paint, glass or metal. Delrin® blades have natural lubricity, high rigidity, and mechanical strength. Long-term fatigue resistance when used in repeated impact and are highly resistant to moisture.