High-resistance to Wear and Tear These Allen keys are made of high-grade alloy steel and are hardened and tempered so that you can perform tough fastening applications without any damage to the keys. Content Size - 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm Accurately Hardened and Tempered to Withstand Higher Torque and Enable High Wear Resistance. Taparia brings this set of 9 Allen Keys that are designed to let you avail two advantages that are important in fastening jobs. You can use the long arm to reach those fasteners that are located in tight spaces. Using the short arm lets you extract more torque to complete your fastening task with ease. High-resistance to Wear and TearThese Allen keys are made of high-grade alloy steel and are hardened and tempered so that you can perform tough fastening applications without any damage to the keys. Black Finished These hex keys are coated with black oxide to make it resistant to corrosion so that their durability is enhanced.