This set of two volcano microwave cleaner is safe and easy to use. Add water and vinegar till the markings and place in the microwave for 5-8 minutes on high heat. You just watch as the volcano erupts and does all the hard work for you. Afterward, use a sponge, rag or napkin and all the grime comes right off. Helps the outside stay cool and allows you to grip and remove the volcano easily. Available in purple and yellow colors.