The Perfect Fitness LED Arm Band increases visibility and safety while exercising in low light conditions. The adjustable strap attaches comfortably to the wrist, arm or ankle and is easy to wear while walking, running or cycling. The Perfect Fitness LED Armband light has two modes, either continuous light or flashing with up to 72 hours of continuous or up to 96 hours of flashing burn time. Weather resistance construction for increased visibility in any weather condition. Requires two CR2032 batteries (included).