C cell stainless steel cups. 1.029" in diameter, 304 Stainless Steel high wall cup with 112 degree formed cone. These are superior to any aluminum style cup. This C cell size is smaller than the 1.034" cup for some Maglite housings. Each cup is .570" long and slightly nest into one another for a perfect seal. These are strong, lightweight (0.3 ounces each) and corrosion resistant. These are sold individually so select the quantity you need.