CR1620 is a lithium manganese dioxide (Li/MnO2) battery, manufactured by Renata, a Swiss-based electronics company. This battery features a nominal voltage of 3.0 volts, a capacity of 20 mAh, and a fast discharge current of up to 800µA. This battery is commonly used in a wide range of applications, such as watches, calculators, medical equipment, and remote keyless entry systems. It has a long shelf life and provides reliable performance, making it an ideal choice for those looking for a power source that they can rely on.