Product Advantages: Drill chuck converter can be installed and removed without additional tools and is easy to use. The drill bit chuck extension can be used for home DIY renovation projects such as furniture installation and repairs, or industrial projects such as car repairs, machinery repairs. The keyless chuck driver can be installed on most electric drills and cordless electric screwdrivers. A set includes 2 different color keyless drill chuck adapters to meet your usage needs. Product Specifications: Material: Carbon Steel Black Chuck Clamping Range: 0.3 - 6.5mm Silver Chuck Clamping Range: 0.3 - 6.5mm Hex Shank Diameter: 1/4 Inch / 6.35mm Package Contains: 2 x Impact Drill Bit Adapter Tips: There may be a 1-2mm error in manual measurement, please don't mind. After-Sales Guarantee: Aracombie has a 24-hour human customer service. If you have any questions before purchasing or are not 100% satisfied with the product, please feel free to contact us, and we will provide you with solutions as soon as possible.