The first letter(s) of a Denso, NGK and Bosch plug code is the thread size identification. Denso: X, XU.
Sealey Spark Plug Socket 16mm 3/8" Square Drive Thin Wall Spark Plug Socket
14mm Back Tap Spark Plug Thread Repair Tool M14x1.25 Thread Chase Tap
Spark Plug Thread Repair Kit – 14mm Reamer Thread Repair Tool &4 Inserts
1Set Stainless Steel Spark Plug Thread Repair Tool with M10x1.0 Thread Inserts
