Designed for 1/2-inch or 21-mm hex keys, this hex key extension tool ensures a seamless connection and broad compatibility with standard hex-head screws and nuts across various sizes. Broad application Widely used in auto care and installation of mechanical equipment, it supports professional machine repairs and everyday home maintenance, making it a versatile assistant for multiple scenarios. Practical upgrade Features an efficient plug-in interface that speeds attachment, saving time and streamlining your workflow. Durable construction Made from high-strength alloy steel, it offers excellent wear and impact resistance for long service life in demanding environments. Use scenarios - Reaching tight engine bay fasteners during auto maintenance and repair - Assembling or servicing automotive components and mechanical equipment - Everyday home repairs and routine maintenance in the workshop or garage A reliable, durable extension tool for consistent performance.