You can easily use the flash light (flashlight). You can check battery level and device temperature. Capacity is easily very small usage. Anyone is easily available because it was paid only always necessary functions. Dark, power failure, when leave work time road is dark, you can use, such as in an emergency. Also, sleeping in the evening and dawn, if you happened, you can see what you need by simply bright and without the fluorescent lamp. Available from any device with a flash feature. Usage