Klein Tools' 9/16-Inch Hollow Magnetic Color-Coded Power Nut Driver was designed with the professional in mind. The 3-3/4-Inch (9.5 cm) hollow core facilitates work on threaded rod by enabling easier access to nut. Made of high-grade impact steel and is color-coded for easy identification. The nut driver contains Rare-Earth magnets to securely hold fasteners, and is also extra long for greater reach.