Klein Tools 632 Drive-A-Matic Cushion-Grip Nut Driver Automatically fits 15 different nut and screw sizes Hex head adjusts to the proper size as you turn it Full hollow shafts facilitate work on stacked circuit boards or other long bolt applications Cushion-Grip handle resists slippage which allows you to apply greater torque Overall length: 7 inches (178 mm) when open, 6-3/4 inches (171 mm) when closed