glass cutter carbide wheel tip, metal shank supply spare head to replace Cut life: 8,000 -10,000 meters Glass cutterFixed with high quality ... tungsten carbide wheel in the glass cutter, and widely used in flat glass, stained glass etcSpecification for your ref: Product NameGlass CutterFeaturesOil ... is metal,very durable3. Serve life: 10,000 meters stained glass tools bottle cutter