A flashlight is a portable lighting device that dates back to the late 19th century, when battery technology was still very primitive. At that time, flashlights used combustion batteries, which had low brightness and short usage time. As we continue to innovate and advance with technology, we have made breakthrough progress. We now use high-quality XHP90 LED bulbs, which provide high brightness, low power consumption, and a long lifespan. Additionally, we use high-quality batteries with excellent electrochemical properties, such as high energy density, good safety and stability, and support for high-current discharge. These batteries (2600mAh*2) greatly extend the usage time of our flashlights.