Comprehensive Resin drill pen set Includes 15 mini twist drill bits of assorted sizes: 0.7x2, 0.9x2, 1.0x5, 1.2x2, 1.5x1, 2.0x1, 2.5x1, 3.0x1. Also features 4 grinding heads with a handle diameter of 2.3 mm and an average length of 32 mm. This combination provides a tool set suited for all your DIY crafting needs. Efficient and laborsaving: An electric handheld drill that significantly improves the DIY crafting experience. It saves time and effort, increases precision, and delivers quality results. Variety of 15 drill bits: The 15 different sizes cover a range of applications from resin casting and jewelry making to keychain crafting. Each bit is designed for different crafts to meet diverse project requirements. Wide applications: The mini drill bits can penetrate wooden boards, plastic boards, and paper sheets up to 10 mm thick. They are not suitable for drilling hard materials such as steel, making this tool ideal for lightweight, precision work. Use scenarios: Resin casting and jewelry making: drill precise holes in small resin pieces or components. Keychain crafting: create clean holes in lightweight materials for assembling keychains. Small wooden or plastic crafts: perform accuracy drilling on thin boards and sheets up to 10 mm.