These optic shoelaces increases visibility so you can be seen by vehicles after dark when running, bicycling or walking your pet. These optic LED shoelaces are available in seven stock colors and have three modes of lighting. The battery pack is positioned in the center of the shoelaces and gives you easy access to turn them off/on or change the mode of lighting. These are weatherproof, washable and durable. Installed lithium battery is included and should flash for approximately 70 hours.