Carlyn Performance 8mm(5/16") Nut Driver with Premium Flexible Shaft for Hose Clamps and Fasteners 8mm(5/16") Hex Nut Driver is perfect for 1/2" and 9/16" wide standard American style hose clamps. Flexible shaft allows driver to be used in tighter spaces than traditional drivers. Comfortable and great looking black and red handle is easy to grip. Special handle compound provides great grip so nut driver doesn't slip. Designed for both professional and DIY use.