[High-quality materials, quality assurance] Drill holder and cone drill are made of high-quality HSS stainless steel, durable. Operation suggestion: When using the electric drill, it should be as vertical as possible, do not shake or tilt, and the electric drill should not rotate too fast. 【Save time and labor, efficient and fast. The HSS cone drill is made of high speed steel, which can reduce heat and friction, cool quickly, and automatically remove debris in the hole when drilling. The spiral design can prevent slipping and make drilling easier and more efficient. 【Three sizes for your needs】 4mm-12mm, 4mm-20mm, 4mm-32mm, you can choose different drill bits according to your needs. 【Wide range of applications] The product can process thin iron plates, aluminum, insulation boards, PVC boards, wood boards and other materials with a thickness of no more than 3 mm【The nylon cloth bag is convenient to carry. The product is equipped with a nylon cloth bag, which can achieve a good