With different inserts this makes swapping inserts a breeze. No more guessing, misaligned parts, or damaged o-rings while you try to hold them all together. In addition, it adds protection so no debris can fall through the spark plug opening.
For spark plug changes, leave the plug in until the head is completely installed and ready for the spare plug.
When swapping inserts: Remove spark plug, install FactoryONE head insert tool (finger tight only) and remove the head bolts. Then, the entire assembly can be removed and installed as one unit.