Klein Tools 640-3/8 3/8-Inch Coated Nut Driver with 3-Inch Hollow Shaft and Cushion Grip Handle Entire shank plastic coated for circuit protection only. NOT INSULATED Special plastic coating resists cutting, cracking, and chipping Thin coating permits use in confined areas Full hollow shafts facilitate work on stacked circuit boards or other long bolt applications Internal flanges provide solid, twist-resistant shaft anchor