Builders, mechanics, glaziers, assemblers and electricians find the CRL Magnetic Screwdriver almost indispensable. It drives any 1/4 inch (6 millimeter) hex head screws or hex nuts. The magnetic force holds insert bits securely, yet bits are easily changed. Comfortable fluted plastic handle. Each of the three screwdriver sizes come complete with four insert bits: #1 and #2 Phillips, #4 and #8 Slotted.