The Tadiran TLL-5902 iXtra Series is an improvement of the Xtra series for long term high performance. Perfected through 25 years of research, developments and manufacturing expertise, Tadiran lithium thionyl chloride cells outperform all competitors. Tadiran TLL-5902 will out perform Xeno and Saft batteries in Maximum Continuous Current. Meaning you will usemore power over a longer period of time. Their unique design allows Tadiran batteries to pack more power into less space, which equals unparalleled reliability, long life and powerful performance. TLL iXtra Seies is designed for faster voltage recovery after long term storage and/or use. TLL-5902 is a better high performance battery for TL-5902, TL-2150, TL-5101, TL-5151