1. High-Performance Drilling: The 3PCS external cooling carbide drill bit set features a non-standard diameter of 3.00, 4.0, and 5.0 mm, ensuring reliable performance for various drilling tasks. (3x14x50xD4 4x18x50xD4 5x20x50xD5) 2. Durable Solid Tungsten Construction: Made from solid tungsten steel, these drill bits provide enhanced durability and extended service life, suitable for both professional and DIY use. 3. Effective Cooling Design: Equipped with an external cooling structure, these carbide drill bits help maintain stable temperatures during operation, improving cutting efficiency and tool longevity. 4. Versatile Application: Ideal for use on multiple materials, this 3-piece carbide drill bit set works effectively on metal, wood, and plastic, offering flexibility for a wide range of projects. 5. Precision Engineering: Each drill bit is precision-manufactured to ensure accurate and clean hole drilling, making it suitable for applications requiring consistent performance with non-standard diameters. Color: As shown Material: Tungsten steel Package Contents: 3 x External cooling carbide drill bit Note: The package includes only the items listed above. Other accessories are not included. Due to lighting effects and monitor settings, the actual color may vary slightly from the image. Measurement may vary by 1-3 cm.