Not just the vials . . . the clean water system also. Nothing can rival MMTC reverse the water sytems and filters. In order to test properly, water must have nothing in it. It is space age miraculous, if you tell me. The clean water system first launched MMTC some years ago. However, other clean water systems became too competitive. Now MMTC can earn their money selling it because NO ONE has yet to match the kind of clean water these machines make . . . no one!