Procell PC1604 Constant 9V Alkaline Batteries, 12 PackEngineered for professional use, these batteries deliver dependable, long lasting power to low drain devices such as smoke detectors, carbon monoxide detectors, multimeters, medical devices, and microphones. Designed to withstand extreme temperatures from 4F to 129. 2F, these corrosion resistant batteries meet strict quality and safety standards while being mercury free for a more eco friendly option. With a 10 year shelf life, date coded packaging