This set of 9 BLACK+DECKER BDHT0-71628 hex keys features a specially designed triangular handle for compact storage and efficient force application. These keys are made of high-quality chrome vanadium steel, ensuring long-term durability. The sizes of the keys included in this set are: 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 4.5mm, 5mm, 5.5mm, and 6mm. With this set of keys, you can efficiently and accurately perform a wide variety of tasks.