Duracell special application batteries offer reliable, long-lasting power You've come to expect from Duracell | And you can be assured its a battery you can trust since Duracell is the No.1 trusted brand of pharmacists and medical and office professionals | Ideal for high-drain devices | Duracell precharged AA 2500 mAh batteries | Stays charged for up to 12 months whilst not in use | Long-lasting NiMH rechargeable batteries are a cost-effective power option | Hours of use in a wireless mouse: 85 Hours | Hours of use in a wireless game: 24 Hours | Duralock Technology Stay charged up to: 12 months after charging | Pack of 4