Features: Engineered for precise, this electric grinding features a stylish four jaw copper design that securely grips various drill bits, ensuring reliability performances during extended grinding and drilling operations. The brass constructed assembly offer keyless accessory replacement compatibility with multiple power tool attachments, featuring a auto centering mechanism for quick installation and enhanced tool stability. Ideal for professional mechanics, handmade enthusiasts, and workshop technicians requiring versatile solution for rotary tools, engraving machines, and bench grinders. Perfect for metalworking projects, jewelry polishing, wood carving tasks, and precise model making where consistent bit alignment and shaking release operations are critical. This comprehensive 10 piece set includes multiple collet sizes (1/8" to 1/4") with steel reinforcement collars, designed to withstand high speed applications up to 30,000 RPM while maintaining grip integrity. Specifications: Color: Yellow/Silver component: Brass/steel type: 2.35mm/3.0mm/3.2mm/4.2mm/4.8mm Suitable for polishing and grinding tools such as electric grinding, electric drill, engraving machine, and so on. Package Includes: 6/10x electric grinding accessories electric grinding head note: Please allow 1-2cm errors due to manual measurement.  Please allow for slight color differences due to different display resolution