Screwdrivers come in a large variety of shapes and sizes to match those of screws. If a screwdriver that is not the right size and type for the screw is used, it is likely that the screw will be damaged in the process of tightening it. Many screwdriver designs have a handle that can be used with different tips. The shaft and the tip can be removed from the handle, and a different one can be attached instead. The shaft and the tip are together called a "bit" (as with a drill bit). This allows a set of one handle and several heads to be used for a variety of screw sizes and types.