High-quality MaterialThe socket set for impact driver is made of high-quality chrome-vanadium steelwhich has extra high hardness and good abrasion resistance. With the polished corrosion-resistant sandblast finish to make it more durable. Easy to UseThe nut driver bit set is easy to be installed and dismantled not easy falling off when it was using. The nut driver socket set is high occlusion tight and flexible. Each socket has an obvious size mark you can quickly find the socket you need. 1/4" Hex ShankThis hex shank bit socket metric is suitable for installing in those hexagon tools such as a pneumatic screwdriver electric screwdriver pneumatic drill electric drill pistol drill manual screwdriver and more. Size Ranges7 pcs power nut driver bits(Inch): 3/16" 1/4" 9/32" 5/16" 11/32" 3/8" 7/16"; 7 pcs power nut driver bits (Metric): 5 mm 5.5 mm 6 mm 7 mm 8 mm 10 mm 12 mm. The multiple sizes of hex drill bits set are sufficient to meet your daily needs.