1.magnetic tip shaft,1/4''DR magnetic nut setter size 5/16" 2.material:CRV steel 3.surface:sandblacted 4.long life 1.magnetic tip shaft1/4''DR magnetic nut setter size 5/16"2.material:CRV steel3.surface:sandblacted4.magnet6.length:65mm,75mm,100mm,150mm7.size:6,7,8,9,10,11,12,13,1/2",5/16" ,