Procell PC1604 Alkaline Constant 9V Battery Box of 12Procell Alkaline Constant 9V industrial batteries are ideal for powering low drain professional devices which require constant current over a long period of time such as smoke carbon monoxide detectors. Features: Save your business money up to 20% by switching to Procell dual portfolio Procell Constant for low drain devices and Procell Intense for high drain devices (Estimated savings versus relevant competition). Use up to 30% fewer batteries by