Amazon.co.jp: Plug Wrench (Set of 2) Spark Plug Socket, Spark Plug Wrench, Thin-walled Removable Tool for Exchanging Automotive Plugs (0.6 inch (14 mm/16 mm) : DIY, Tools & Garden
Amazon.co.jp: Spark Plug Screw Repair, Easy to Operate Spark Plug Thread Reamer, Heavy Duty Spark Plug Tap, Service Repairer General Purpose Professional Use : Automotive