Sky Rocket Fuze Wheel Writer 2, 20'' Inch Wheel and Up Preloaded with up to 64 different images and animations. Or, create your own pictures, animations and text to display in your bike wheels using your iPhone, iPad or iPod Touch The Fuze Wheel Writer mounts directly to spokes ( 20'' wheel and up) and works best when riding more than 10 mph. Real working speedometer The accessory is equipped with super bright LED lights, don't worry about puddles or wet roads as the Wheel Writer is water-resistant Ride in style and impress your friends with this fun bike accessory