Product size: The carbon brush size of this product is 4mm long, 3mm wide, and 3mm high. Manual measurements, please allow slight errors. Compatibility: This product is Compatible with Marathon Nail Drill Electric Manicure Machine Easy to install: It can be directly replaced without adjustment, with perfect compatibility and high reliability. Product material: This product is specially designed and made of metal material, with a long service life and not easy to damage. Product list: Product include a total of 4pcs Carbon Brush, which can completely meet your daily use needs and replacement., Manufacturer: SG Store