This 7.4v battery fits the Cool Shirt Waist Pack Cooling System (Part No. CS2013), but the 4.4 Ah capacity lasts longer than the original 2.2 Ah battery. This battery is a little larger, so it gets installed in the pouch in front of the pump instead of next to it.
The 7.4v Battery Charger (Part No. CS430) is sold separately.