The Powerbuilt 4 Piece 3/8 Inch Drive Socket Extension Bar Set is the perfect socket extension combination. The four-piece extension bars set comes in 1 3/4 inch, 3 inches, 6 inches, and 8 inches, to maximize coverage. They are made from high-quality Chrome Vanadium steel with a mirror-polished chrome-plated finish for durability and long tool life. This 4 piece set of extensions are perfect solution tools for when accessing hard-to-reach places like when working in and around engines, under the chassis, or any other jobs that require a long reach in a tight space. Each extension features knurling on the center of the shaft for a secure grip to allow for quicker rotation when tightening or loosening fasteners. No need to worry about dropping sockets in narrow spaces the Powerbuilt extensions also feature spring-loaded detent balls to help lock into and secure the sockets.