At this moment the smallest of my kilns, the JD-18, the one that we put in the quad element sides, is in the middle of firing number 121 on that set of elements. Wow! I fired it last night on an end ramp of 350°F to 2350°F and it could not quite keep up, but I normally do not fire it anywhere that fast. It needed a new relay at around firing 100, but has been going strong ever since. You predicted 200 firings on that set of elements, and we just might get there.