This replacement Sanik NiMH Battery 2SNAAA55HSJP1 are  replacement for your old cordless phone battery packs. This 2.4V 550mAh NIMH rechargeable Sanik cordless phone battery is also known as 2SN-AAA55H-S-JP1. This is a upgrade to 800mAh Which just means it will give a little longer talk time.