The Craftsman CM-100PC Hex Key Set is a comprehensive set of 100 hex keys in a variety of sizes, including SAE and metric. The keys are made of hardened steel and are chrome-plated for corrosion resistance. They also have a comfortable grip to make them easy to use. The set includes a variety of sizes, from 0.050? To 1.50? , so it is perfect for a wide range of applications. It is also a great value for the price. HI PIECE COUNTS: To fill your tool chest. DURABILITY: Strong steel hex keys with black oxide coating. EASE OF USE: Chamfered edge helps guide the wrench for a smooth, easy entry into the hex key. STORAGE: Convenient storage racks keeps individual sets together in your toolbox. APPLICATIONS: carpentry, electrical, mechanical, plumbing DIY and MRO.