Duracell MN21 Batteries are multi-purpose alkaline Batteries ideal for reliably powering your everyday devices.-Long lasting guaranteed-Suited for wireless remote controls, wireless doorbells and security systems (alarms, locators)-Duralock technology, up to 5 years in storage-Leakage prevention-Commercial guarantee vs. the Minimum Average Duration across 2015 IEC MN21 battery tests. Results may vary by device or usage pattern. (www.iec.ch)