A toothpick works for checking the center of a cake, but it does not tell you much about how the edges are setting relative to the middle. A metal cake tester is thinner, so it leaves a smaller hole, and long enough to test at different depths in one motion.
Clean pull means the crumb has set. A wet pull means more time. Simple.
Reusable. Stainless steel. 7.8 inches long. Stores next to your thermometer and gets used every time you bake a cake.
