the size of the bread is ideal, then press this button to begin bake. Otherwise if something is wrong and the machine begin to bake when the bread is not big enough, the taste is totally different. I dumped the first one bought at WalMart(used it many years anyway) for this reason and bought another one with this button. Of course, if the lady can make it just right everytime, then no worry.
Another feature: the type that is lower and wider (so the bread is lying down, not stand up right) makes much less noise than the up-stand one.
Another feature: the type that is lower and wider (so the bread is lying down, not stand up right) makes much less noise than the up-stand one.