TEKTON 4970 1/2-Inch Drive Impact Extension Bar Set, 3-Piece Designed for use with air tools Forged and hardened carbon steel with a corrosion-resistant black oxide finish Hole on extension bar locks onto drive tang and a spring-loaded ball bearing locks onto sockets Set Includes: (3) 1/2-Inch Drive Impact Extension Bar: 3, 6, and 8-Inch Lifetime replacement guarantee