The 4pc 3/8” drive tune up kit offers the essential items for replacing the most common size spark plugs. Full polish chrome spark plug sockets in 5/8” and 13/16” size featuring full polish chrome finish easily wipes clean and resists corrosion and large stamped size markings for easy identification. Included also is a 3” full polish extension bar, with a knurling and a ball detent for secure socket retention. The 84 tooth offset flex head ratchets have a 4.3° swing arc for ultimate access, a flex head design to for better and access and offset handle design for even more additional angled access.