X-ACTO X511 500pc X-Life Blue Blade No 11 Classic Fine Point Knife Blades. X-Life Blades are made from the highest quality carbon steel, rigidly tested for hardness, and manufactured to the most stringent specifications. They are oxidized to resist rust and increase durability. Based on independent tests, the X-Life blades show a 30 percent sharper edge and have 54 percent longer life than competitive blades. For delicate, precision cutting, detailing, trimming and stripping. Paper, plastic, balsa, and bass wood. Fits 1/4 inch Type A X-ACTO or Excel Handles. Packaging may vary. Made in USA.