LED flashlight(usually called a torch outside North America) is a hand-held electric-powered light source instead of conventional light bulbs. It has longer battery lifetimes, in some cases hundreds of hours, although the LED efficiency advantage diminishes at higher power levels. Typical flashlight designs consist of the light source mounted in a parabolic or other shaped reflector, a transparent lens to protect the light source from damage and debris, a power source (typically electric batteries), and an electric power switch. LED flashlight is often electronically regulated to maintain constant light output as the batteries fade. By contrast, a non-regulated flashlight becomes progressively dimmer, sometimes spending much of the total running time below 50 percent brightness level. While most flashlights are hand-held, there are head or helmet-mounted flashlights designed for miners and campers and battery-powered lights for bicycles. Some flashlights are powered by hand-cranked dynamos or electromagnetic induction or are recharged by solar power. The LED flashlight is widely used in the car, home, work, camping, emergency kits, etc.