20x Exell A21PX 4.5V Alkaline Battery 523 EN133A PC133A PX21 1306AP, Exell Batteries not only provide consumers with high efficiency, long-lasting performance, they also function as Compatible With batteries for an array of common and unique applications. Ranging from vintage camera equipment to sophisticated testing equipment, Exell Batteries can meet the needs of all consumers.The A133, or 523, battery is an unusual cell often used in classic cameras. It is used to maintain computer time, date and configuration in certain models of Macintosh computers (Parameter Random Access Memory, Parameter RAM, or just PRAM). This PX21 battery has an NSN number of 0000-00-000-0000 and a US Military part number of BA-1098/U.• Type: Alkaline • Voltage: 4.5V• Amperage: 600mAh• Diameter: 16.8 mm • Height: 49.9 mm• Terminals: Flat ContactsAlso Known As: 1306AP, 3LR50, 523, 0000-00-000-0000, A21, A21PX, A133, APX21, BA-1098/U, EN133A, EPX21, PC133A, PX21, RPX21, V21PXSpecificationsOutput Voltage: 4.5V, Amperage: 600mAh, Chemistry: Alkaline, Height: 49.9mm, Diameter: 16.8mm, Terminal Type: Flat Top, Country of Manufacture: U.S.A.A21PX. ALSO USED IN: 1306AP, 3LR50, 523, 6135-99-114-1239, A21, A21PX, A133, APX21, BA-1098/U, EN133A, EPX21, PC133A, PX21, RPX21, V21PX, Syncron AU7a condenser microphone Digitech DSP-256XL Mallory TR133 Polaroid 268 flash Polaroid Automatic 100 Praktica 35mm SLR EE2 Digitech GSP21 guitar signal processor PX21 Novacell NV3LR50 Novacell NV 3LR50 Rohrback Cosasco Systems Model CK-3 and MORE. FOR USE WITH: Classic cameras, it is used to maintain computer time, date and configuration in certain models of Macintosh computers (Parameter Random Access Memory, Parameter RAM, or just PRAM).