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 exceptional performance for various drilling tasks. (3x14x50xD4 4x18x50xD4 5x20x50xD5) 2. Durable Solid Tungsten Construction: Crafted from solid tungsten steel, these drill bits offer superior durability and longevity, making them ideal for both professional and DIY applications. 3. Effective Cooling System: Designed with an external cooling mechanism, these carbide drill bits maintain optimal temperature during use, enhancing cutting efficiency and prolonging tool life. 4. Versatile Application: Suitable for drilling into metal, wood, and plastic, this 3PCS carbide drill bit set provides reliable performance across a range of materials. 5. Precision Engineering: Each drill bit is precision-engineered to deliver clean, accurate holes, ideal for applications requiring consistent results 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. Light reflection and display differences may cause slight variations between the image and actual color. Measurement may vary by +/- 1-3 cm.