This drill bit extension kit is made of industrial grade heavy-duty stainless steel, durable, withstanding high pressure. Great for extending all kinds of screwdriver bits, drill, batch head, screwdriver head conversion uses. Features - Material: Stainless steel. - Made of stainless steel, not easy to rust, , good corrosion resistance, high wear resistance, high hardness. - Great for DIY work, household maintenance, and most general repairs, not for industrial work. - Allowing you to bring your bit extensions anywhere to get any jobs done, regardless of what type of power drill or driver. - It is manufactured with technology to ensure the high- of the product and can work for a long time. - You will have a good use experience because of the perfect workmanship of this product. Package list: 2 sets x bit holders