Power Stack Duo in friendly orange and black colouring is a three-part set consisting of heavy-duty batteries. They can be stacked together, providing one multiply-reinforced battery with power reserves for high demands. When charged as a stack, the Top-Is-The-King principle applies: as the element on top of the stack has priority in charging, the operational component can be simply removed and used. Two cables with Lightning USB and one with micro USB connectors are integrated. Each element offers individual capacity.