DescriptionPrototype drawing of a size AA, Mallory Alkaline Duracell battery, MN 1500, 1.5 Volts. The bottom right-hand corner has a stamp with drawing information written in black pen. Some letters are smudged. Typed onto the back in black ink is "892306". Made on green-backed, Crescent Illustration Board, Hot Press Surface, No. 201, Medium Weight.