Pack Quantity: 10 | 6LR61 | 9VProcell Alkaline Constant Power 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.Longer lasting power in low drain professional devices, vs. prior Procell 9V batteriesAlkalinePackaged for professional use - date coded for easy inventory managementAlso available in AA, AAA, C, and D sizes