The rodsleeve is designed to focus the pounding energy of the driver downward. Simply slip the rodsleeve into the tail piece of your driver and you are ready to go. The rodsleeve will hold the grounding rod / rebar center to the blows of the hammer controlling vibration, channeling the trust of the hammer in a downward direction. Rodsleeves come with a standard bore of 1". Custom sizes are available. Telephone or email us for more information. Use this insert with Redi Driver Boss.