Amphipod Micro-Light Flashing Reflective Armband - Green Fits on your arm or ankle, and can be strapped to a backpack or bicycle 4 separate red LEDs and end-to-end reflectivity catch the eye of oncoming motorists Turn the LED on and off with a simple press of a button Amphipod Micro-Light Flashing reflective armband operates on a single CR2032 battery (included) that's easy to replace