Duracell Ultra Alkaline 9V Battery, 12 Pcs usually used in smoke alarms, smoke detectors, walkie-talkies, transistor radios, test and instrumentation devices, medical batteries, LCD displays, and other small portable appliances. Long Lasting Power Guaranteed Our best battery, suited for everyday devices with extra performance for high drain devices, Duracell technology keeps unused Duracell batteries fresh and powered for up to 5 years