Replaceable:4 Pack Tungsten Carbide Tip Scriber with 4 free replacements marking tip. Durable Material: The glass scriber has a durable tungsten carbide tip and an aluminum body, so it can easily handle hard materials including hardened steel, stainless steel, ceramic and glass. Disposable briquetting tungsten carbide blades are more durable than others and are not easy to drop. Magnetic: The permanent magnets on this etching tool pick up small parts and recover steel filings from hard-to-reach places. Comfortable Use: Convenient pen design and convenient pocket clip, knurled aluminum handle provides maximum control and comfort. Easy to Store: When not in use, the tip of tungsten carbide can be reversed.