Stay equipped for all your outdoor training with the "PowerArmz" arm band. This lightweight, adjustable armband is powered by high intensity LED lights that will make sure you are both safe and visible. Its weatherproof design lets you use it even in the most extreme conditions. Features: - Batteries included, Uses 2 CR2032 batteries. - Ultra Bright LEDS - 70 hours steady operation - 100 hours flashing burn time - Weatherproof