Model:ER18505 International size: A Nominal voltage:3.6V Dimension:φ18.50mm*50.50mm Can replace A size batteries such as: Tadiran XL-100F,, Saft LS-17500, Sonnenschein ER17500V, Xeno XL-100F. This A Lithium Thionyl Chloride battery with polarized pcb pins is ideal for and widely used in wireless alarm systems, memory backup for computers and night vision equipment. This A Lithium Thionyl Chloride battery is mounted into a variety of monitoring equipment because of the long life and high energy content of the battery. The A Lithium Thionyl Chloride battery with polarized pins is ideal for these applications. Lithium Thionyl Chloride has the highest energy density of any practical Lithium battery chemistry, three times greater than Alkaline (Zinc Manganese Dioxide) batteries. It also has the widest operating temperature range of -55°C to + 85°C. Self discharge is low at less than 1% per annum at 20°C, giving an effective shelf life of 10 years