With the STEELMAN PRO 79989 3-Piece 1/2-Inch Drive, 3/8-Inch Pinless Swivel Impact Extension Set, youll be able to access hard-to-reach spaces where maximum power is needed. The set includes three swivel-tip extensions; one each at 6-inch, 9-inch, and 12-inch length. Made from premium quality, heat-treated 4140 chromoly steel with black oxide finish these extensions are designed to hold up to long use. Compared to a universal joint design, the pinless joint design found on these adapters transfers more useable torque to fasteners while adding safety by preventing projectiles common to other designs in the event of accidental breakage. The swiveling heads on these adapters provide a high degree of flexibility, allowing for a wider range of applications.