Includes: 3 pieces 3/4" drive extension bars:4", 6", 10". Made of impact grade chrome molybdenum steel with black phosphate finish,more durable and sturdy. Spring-loaded ball at male end retains sockets securely and prevents them from dropping, ball hole at drive end locks onto drive tang of impact tools This impact extension bar gives your impact wrench and sockets the extra length needed to work in hard to reach areas. Ideal tools to access hard-to-reach fasteners in tight spots, especially for trucks and tractors. All Mayouko Tools meet or exceed ANSI & DIN performance standards. It comes with 1 year quality guarantee. Our extension bars are constructed from a high quality cr-mo steel that is made to withstand high amounts of torque with impact tools for breaking loose tough fasteners. Versatile for Automotive Applications Set includes three bars with varying sizes to give your impact wrenches an extra reach for narrow and tight fasteners. Ideal for use on trucks and tractors that feature hard to reach lug nuts.