I cant seem to find these things to save my life, but I know I have seen them before. Might be a little hard to explain, but its a piece that you can slip over a spark plug and then use a wrench to tighten the plug into the head. The usually come in a kit of 3 (different lengths) and they work great when you cannot get a regular socket over the end of the spark plug and you cannot fully tighten the plug with a wrench. I need a set for 5/8" hex spark plugs. Anybody know where to get these things?