I use these in my Simplicity riding mower / tractor. Great little plug. The engine starts on the first turn of the key (as long as the battery hasn't died over the winter). Last time I bought a box of these was in 2003. Two tune ups in 13 years providing a super well running old engine is a real testament to these plugs.
Why do they stop making GREAT plugs like these ? Same thing happened to the Bosch 4 banger plugs I use on my Honda Civic. So glad I can find auto suppliers on Ebay who still carry them.