SAFT 2/3 A size Lithium Thionyl Chloride Cylindrical Cell, High energy, high reliability 3.6 volt power source, Excellent memory backup power source, Low self discharge rate gives this cell a 10 year shelf life. Stable voltage and broad temperature range (-60° to +85°C), MSA GAS, ER17/33, ER17335, LS17330, LST17330, T32/41, T32/51, T32/8AA1