There is an important difference between a gas grill and an oven, it's that the grill gets much hotter than the oven and thus creates those yummy carcinogens that you want from a grill.

I went from using a coal fired Weber to gas fired Weber and there is no taste or quality difference that I can detect, but the gas grill is much more reliable and will stay the correct temperature for as long as I need it, unlike the coal grill.

It's a counter of some sort.

Each wheel will make the next advance one tooth for each rotation.