The LR626 battery is a small, button-shaped alkaline battery that is also known as an AG4 or 377A battery. It has a nominal voltage of 1.5 volts and a capacity of approximately 20 milliampere-hours (mAh). The LR626 battery is commonly used in small electronic devices such as watches, calculators, and remote controls. It is important to note that the LR626 battery is not rechargeable and should not be disposed of in fire or with household waste. Ideal for vernier callipers Laser Pointer, Hearing Aids, Insulin Pumps, Heart Rate, Monitor, Watches, Cameras, Calculators, Car Security Alarm, Keyless Car Remotes, Organizers, Glucometer, Computer Equipment (memory backup battery) CMOS, Toys, Communication Equipment, data pack for video cameras, and other devices that requires this battery size!