1.FUNNY BIKE BELL: There is a air screw on the helmet, it will fast rotate when you cycling. You need to have a special and unique bike bell for your bike, here it is. | 2.UNIQUE DESIGN:Duck bike bell design with 12 lumen yellow lights,45 decibel sounds, press or pinch the duck bell tail, and it will scream up. | 3.EASY TO INSTALL:First, pull the bottom band of this duck bells and twine it on your