The 7.4V, 3900mAh Li-Ion Battery Pack for DS125 / DS160 / DS161 Substrobes from Ikelitepowers the DS125, DS160 and DS161 underwater strobes. It has a voltage of 7.4V and a capacity of 3900mAh. Low internal resistance enables it to provide up to twice the number of flashes per charge and an even faster recycle time than that which is possible with older NiMH cells. The battery is 18% lighter than the 4066.5 NiMH battery pack, which makes the strobes neutrally buoyant in saltwater. Its depth rating is 300' (91.4 m). Several redundant safety features prevent the battery from overheating or exploding, which is especially helpful when traveling. Charge it via the optional 4067.1 Smart Charger.