Neon Nightlife LED Light Up Bike Wheel Lights 2 Pack - Includes lights for both wheels on a bike. 3 AAA batteries included. Lights last over 24 hours on a new set of batteries. Installs in approx. 5 minutes (instructions included). Battery pack mounts to center wheel hub. Lights & battery pack feature a water resistant construction. Batteries can easily be replaced without removing battery pack from wheel. Battery pack has on/off/flash modes controlled by a button. 7 feet of LED lights. Supports most standard wheel sizes.