Yes, and they are a glow plug drilled out and fitted with a copper plug. The idea behind them is to let someone explore running their engine on diesel to see if they like the whole diesel concept without spending a lot of money. While they run, they do not run at optimum setting as they are non-adjustable and every engine is different. As an experiment, they are fun, but for practical use (like flying an airplane) they are not worth a crap.

Max