Features 1、[Versatile Length Options] The drill bit extension set includes four different lengths: 50mm, 100mm, 150mm, and 300mm, meets a wide range of drilling needs. 2、[1/4 Inch Hex Shank] With standard 1/4 inch hex shank, the drill bit extension bar can be easily and securely connected to power tools, allowing for quick setup. 3、[Strong Magnetic] The drill bit extension features built in magnet that securely holds the drill bits in place, convenient for drill bit replacement. 4、[Alloy Steel Construction] The drill bit extender is crafted from premium alloy steel material, sturdy and robust, ensures long lasting durability. 5、[Integrated Structure] The integrated structure of drill bit extender maximizes force concentration, ensuring the longevity of the product. Specification Item Type: Drill Bit Extension Set Material: Alloy Steel Size: Approx. 50mm / 1.97in, 100mm / 3.94in, 150mm / 5.91in, 300mm / 11.81in Shank: 1/4 Inch Hex Shank Package List 4 x Drill Bit Extension