The Hilti SME Screw Fastening Mag Extension helps extend your reach by approximately 3 feet when used with Hilti's SD M 1 or SD M 2 Screw Magazines and the SD 4500-A22, SD 4500 and SD 2500 Hilti screwdrivers. Attach this magazine extension tube to your Hilti Screwdriver and Screw Magazine, and begin completing your overhead applications with more convenience. Increase your productivity and jobsite safety with this great Hilti accessory.