The SUPER HEAVY DUTY type batteries are made of Zinc Chloride and do not last as long as alkaline batteries, but are also less expensive. These are the perfect batteries for low drain devices such as remote controls, radios, small flashlights, and other electronics that do not demand the long term continuous drain on the battery cells. All types of batteries also come in all sizes. The most obvious and well-known sizes are "AA", "AAA", "C", "D", and the "9 Volt."