Milwaukee 3/8in Drive 6in Extension features the largest knurling surface, providing exceptional control during use. The knurling on the female drive end is designed to assist with hand-tightening and working with oily materials, ensuring a secure grip. Additionally, select extensions include knurling on the shaft for enhanced handling. This extension is chrome plated to superior corrosion and rust protection, making it durable for long-term use. Backed by a lifetime , it represents the quality and reliability expected from Milwaukee Mechanics Hand Tools. Model Number: 43-24-9114