There are different type screwdriver bit heads, like slotted head, head, torx head, hex head. Please see the specification in product description. Magnetic, sucking the screws easily when used it. High precision, each edge can be accurately locked screws, no damage to the screw and the screwdriver head. Fit for electric screwdrivers, hand screwdrivers, electric drills, air drills and so forth. Colour: Silver Material: S2 Steel Size: Shank: 1/4 Inch Hex Shank; Length: 3.93 Inch/ 100mm Package Contents: 16 * Screwdriver Bits Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.