The Great Neck 1/2" Drive Impact Extension Set includes two pieces - a 12" and a 6" extension. Made of durable chrome vanadium steel, these extensions are designed for heavy-duty use and are wear-resistant. The impact sockets are suitable for standard (SAE) measurements, making them versatile for various tasks in a workshop or home setting. With a focus on quality and reliability, this set is a valuable addition to any tool collection for working on fasteners with a socket wrench.