The Exell A640PX 1.5v Alkaline Battery (PX640A EN640A EPX640A LR52) has a distinct appearance with its stepped, concentric disks. This alkaline battery produces 1.5 V. Care should be taken as silver oxide and mercury cells have the same dimension and names as this alkaline battery but with different voltages. Before replacing the batteries, check the expired cell or device documentation if an alkaline 1.5 V battery can be used. The Exell A640PX 1.5v Alkaline Battery (PX640A EN640A EPX640A LR52) is commonly used in gun scopes, transistor radios, and cameras.