PREMIUM MATERIALS - Rockwell Razors Safety Razor Blades are made of premium rust-proof Swedish stainless steel, and specially treated to retain exceptional sharpness. LONG-LASTING - Each blade lasts 5 to 8 shaves. SAFELY PACKAGED - Each blade is double-wrapped in recyclable paper packaging for safety and easy disposal. WORKS WITH ALL SAFETY RAZORS - Provides an excellent shave when used with all double-edge safety razors, including Rockwell Razors branded razors. 4 MONTHS OF SHAVES - This 20-Pack of Blades will last approximately 4 months, assuming the blade is changed once every week.