The SET OF 10 BOSCH LBHX001 Hammer Drill Bit is a high-quality set of drill bits designed for drilling into concrete, brick, and block. Made of durable steel with a gray color, each bit is 4 inches in length and suitable for commercial use with air drills. The Bosch brand ensures top-notch performance and reliability for your drilling needs. Perfect for various projects in home improvement and construction, this set of drill bits is a valuable addition to any toolbox.