These 4.5V Alkaline Battery V19PX 531 RPX19 A19PX EPX19 Batteries not only provide consumers with high efficiency, long-lasting performance, they also function as replacement batteries for an array of common and unique applications. Ranging from vintage camera equipment to sophisticated medical testing equipment, Batteries can meet the needs of all consumers. The V19PX or 531 is an unusual cell often used in older Polaroid cameras. It is a cylindrical battery with one mini snap connectors at each end (the same size of mini snap found in the popular 9Volt PP3 battery). The older Polaroid cameras models: 100, 101, 102, 220, 225, 230, 240, 250, and 340 use one PX19 or No. 531 (4.5 volt) alkaline battery. Type: Alkaline. Voltage: 4.5 V. Diameter: 16.8 mm. Height: 58.3 mm. Also known as: V19PX / 531 / RPX19 / A19PX / EPX19 / 3LR50 / 1307AP.