1- Those Slotted Tip Screwdriver Bits are made of S2 alloy steel which is a commonly used material in hardware 2- Magnetic bits can be firmly fixed on screwdrivers 3- 6 sizes a set at an affordable price can meet your requirements 4Those bits are magnetic that can be firmly fixed on screwdrivers, fitting for electric screwdrivers, hand screwdrivers,electric drills, air drills and so forth 5Type of shank: 6.35mm / 0.25 inch hex