Features: Optional Sizes - offers slotted bits in sizes SL2, SL3, SL4, SL5, and SL6 for you to choose, 10 pieces a set. Standard Bits - 1/4 inch drive bits come in different length 50mm(1.96in) or 100mm(3.93in) for your needs. Magnetic Tip - non-slip magnetic tip helps to prevent from sliding out, easy to attach screw. Shock Resistant - made of heat treated S2 tool steel, high hardness, high torque, solid and sturdy for long term use. High Quality - with presentable blueing surface, the bits are well-made and not easy to fade and rust. Handy Tool - suitable for pneumatic screwdriver, electric hand drill, power screwdriver, and more.