The Tornado 2/3 AA 600mAh 4.8V square NiMH battery is part of Overlander's Premium Sport range. These rechargeable Nickel-Metal Hydride batteries have amazing power in a neat and compact size. The unique sizing of these 2/3 AA cells make them a perfect go-to for applications with limited space. They are also extremely light weight, so ideal for use within small flying models. It really is surprising how much energy is compressed into these batteries.