SpecificationShank Type: 1/4 Inch Hex Shank; Head Type: Hex Head; Total Length: 4 Inches In Length. 8 Hexagon Hex Bits2.5Mm(H2.5) 3Mm(H3) 4Mm(H4) 5Mm(H5) 6Mm(H6) 8Mm( H8) 10Mm (H10) 12Mm (H12), 8 In 1 Professional Size Hex Head Drill Bit Set. The Size Is Clearly Etched On The Bit For Easy Identification. Widely Application1/4" Hex Shank And 4" (100Mm) Length. Can Be Used With Electric Screwdriver, Manual Screwdriver, Electric Drill, General Group Tools, Air And Other Standard Bit Holders. Quality MaterialHigh Quality S2 Steel. Magnetizable Hex Head Allen Bits (New Bits With A Weak Magnet). After Being Magnetized With Magnet, It Would With Strong Magnetic, Can Suck Screws Easily When Used. Exquisite WorkmanshipThis Set Of Hex Bits, Exquisite Workmanship, Each Edge Can Be Screws Locked Precisely, No Damage To The Screw And Screwdriver Head. A Practical Helper In Many Situations.