Great for Briggs and Stratton, Honda, Kawasaki, Kohler, Tecumseh Engines with NGK, Champion, Rocwood, Oregon, Bosch Spark Plugs. Just fit the tool outer rim into the spark plug gap and move it along until it is tight in the gap, this will show what gap you currently have and you can then decide if you need to increase the gap or decrease it.
eBay