The Squishy Circuits Battery Holder, designed for the Squishy Circuits collection, provides power to the circuit. This battery holder can hold 4 AA batteries (batteries not included). It features strong wires with terminals attached to easily and quickly start creating with Squishy Circuits. The label warns not to short the two metal terminals out, but internal circuitry protects from overheating if this would happen. However, it’s best to be careful and not let the metal terminals touch.