ZNU Bike Car Motorcycle Sensor Tire Tyre Wheel valve caps LED Flash Light Green Fit for Car,Motorcycles, Bicycle If the LED flash tyre valve cap does not work,please take it apart and install the button cell appropriately and try it again. vibration sensor, flash automatically when the vehicle moves. Easy for install, just screw it into the tire valve stem of your car, bicycles or motorcycle.Make your vehicle more characteristics. and look cool