Feature 1Screw Bit Set: The screw head set is available for impact controllers and comes in a variety of specifications for replaceable use. 2High Speed Steel: The screw head set is made of hard, high speed steel, which is resistant to wear and tear and has a long life. 3Fine Workmanship: This screw set bit set is of fine workmanship and is fitted for precise adjustment and helps reduce CAM pulsation. 440PCS Set: The screw head set has multiple head sets, which can be used for most manual drill tasks, which is very practical. 5Practical Tool: This set of screw batch heads is a very practical tool to quickly replace different batch heads for easy work.SpecificationItem Type: Screwdriver Bit Set Material: High speed steel .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List21 x 25mm Screwdriver Bit16 x 50mm Screwdriver Bit2 x Hex Socket1 x Magnetic Positioning Extension Bar