Description 1. Innovative Depth Stop Mechanism: Revolutionize your drilling experience with our smart depth stop design. This design features an external alloy ring that is equipped with ball bearings inside. When in contact with wood, it will immediately stop rotating, thereby preventing excessive drilling and reducing material wear. This intelligent function greatly extends the lifespan of your tools, reliably performing for countless drilling operations. 2. Premium Material & Exact Dimensions: This set is expertly constructed from high-grade aluminum alloy for the main body and integrated stop ring, complemented by four precision-engineered carbon steel countersink drill bits for superior strength and heat resistance. The length of this tool is approximately 80 millimeters (3.15 inches), matching the standard 6.25 millimeter (1/4 inch) hexagonal handle size. It is equipped with internal drill bit diameters of 2.8 millimeters (0.11 inches), 3.2 millimeters (0.13 inches), 3.5 millimeters (0.14 inches), and 4.0 millimeters (0.16 inches), suitable for various applications. 3. Precision fabrication: Each tap drill head is meticulously crafted to drill out clean and precise holes. This advanced geometric structure ensures the best chip removal effect and significantly reduces the phenomenon of wood fragmentation, thus enabling the creation of perfect punching results. This allows the screw head to fit perfectly or be embedded within, achieving professional-level quality every time. 4. Adjustable Depth & Broad Compatibility: Achieve consistent and precise hole depths with the easily adjustable drill bit protrusion, which can be set anywhere from 5mm to 35mm (0.2" to 1.38"). The universal 6.25mm (1/4") quick-change hex shank offers wide compatibility with most drills, impact drivers, and quick-change chucks, making this set highly adaptable for various woodworking projects. 5. Optimized Performance for Woodworking: Engineered to enhance your woodworking tasks, this tool set is designed for efficiency and ease of use. The smart stop mechanism, coupled with the sharp carbon steel drill bits, ensures clean and consistent results, providing a reliable solution for carpenters, DIY enthusiasts, and professionals seeking precision in their work. Colors are as depicted in the product imagery. Package list Depth stop set*1