This is a 1.5 volt alkaline button cell battery commonly used in laser pointers, watches, children books, calculators and medical devices. A button cell battery is a small, round battery that is 11.6mm (0.457 inch) in diameter and 5.4mm (0.21 inch) thick. An alkaline battery is a battery that uses manganese dioxide and zinc to create a reaction, and it is an economical alternative to silver oxide batteries, while still providing high capacity and long usage. This is a primary cell battery, and it is non-rechargeable. This alkaline button cell battery provides long power life and excellent continuous power sources to your device. Works effectively in both low and high temperature.