compatibleged from the premium material, so this extension bar has high hardness and high torque, and with the built-in strong magnet and locking device, it can provide you with stable and firm connection without loosening. Since this extension rod can be rotated left and right, it is especially suitable compatible screwing the screw in the small environment, which is labor-saving and convenient to use. This extension rod is mainly made of chrome vanadium steel, which is sturdy and durable. Its length is 87mm and its diameter is 15mm. It can be used with the electrical drills, socket wrenches and so on. Item Name: Hexagon Extension Bar Material: Chrome Vanadium Steel Size Details: 87 x 15mm/3.43" x 0.59" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Hex Extension Bar