This is a 9-Volt battery with reliable, long lasting power for a wide range of important electronics. Each battery provides 9 Volts of electricity to devices such as smoke alarms, garage door openers, alarm clocks and many more. Fast acting alkaline chemistry keeps these batteries going on the job or in storage with a stunning Shelf life. Top that off with Energizer's high quality manufacturing, and you've got a power source that you can truly rely on.