【20PC Hex Bits Set】10PC SAE-5/64”,3/32”, 7/64”, 1/8”, 9/64”, 5/32”, 3/16”, 7/32”, 1/4”, 5/16”,10PC Metric-1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 5mm, 6mm, 7mm, 8mm 【S2 Tool Steel】Meet international standards: tempered at 350-800 deg F to obtain hardness of Rockwell C 58-62, stands up to abuse. ThinkLearn Allen Socket Set 10 times life expectancy versus standard bits. For impact driver and heavy screw driving 【Strong Magnetic Head】Helps you pick up screws easily / locate them more easily and the magnetism will not decay after many uses. Hospitalized black surface - ensures no rust in high humidity environments 【CNC machined tips】and undergo a special treatment process.This ensures long-lasting durability and precision, even under heavy use. Torsion zone to absorb torque peaks to avoid breakage.For impact driver and heavy screw driving 【4"Length Hex Bit meet more needs】Compare with other size hex bit, 4” long drill bits are more widely used in daily life,more practical and convenient, 4” hex drill bits can be easily finish the job in tight space, saving you time and money 【Easy to Identify and Carry】the hex bit come with a hook, that make you carry it easily whether outdoors or indoors, and identify the hex bit by colors, quickly find the hexagonal drill you want through the color 【Widely Used in Daily Life】This 4" hex bit set is widely used in home repair, automotive, other screwdriver applications and consumer electronics repair. Examples include 3D printers, bed frames, motorcycles and cars, RC trucks, bicycles, etc. 20PCS Impact Hex Bit Set (Metric&SAE), 4" Long Hex Head Allen Wrench Drill Bit Set With Holder, 1/4" Hex-Shank S2 Steel Head with Quick Release Bit, CNC Machined Tips with Magnetism