Variety and Organization. What more could you need? The SKIL 148-piece screw driving bit set is packed with an assortment of the most commonly used screw driving bits for a variety of projects. Plus, the patented, Bit Grip Magnetic Bit Collar holds screws securely for one-handed use. Simply slide the collar onto a 2" impact bit for 4X Magnetic Force to hold fasteners securely. Includes a convenient carrying case to keep your bits organized.