M12 x 1.25 Metric Thread Repair Install Tool Insert Kit M12 Helicoil Coil 15pcs

Thread size: M12 x 1.25mm. Thread inserts material: Stainless steel. Thread tap and the drill material: HSS (High-speed Steel). 10PC x Wire thread inserts. To repair a spark plug thread no Pre-drilling is necessary if using the special Spark Plug Tap.