Apollo23 - 2 PCS LED Flash Light Bike Bicycle Car Motorcycle Wheel Tyre Tire Valve Cap light, White LED light length: 2.36 in (60 mm) Motion activated, flash automatically when the vehicle moves. Easy installment, simply screw it into the tire valve stem of your car, bicycles or motorcycle in seconds. Super bright, energy saving and long lifespan LED. Increases night time and bad weather visibility for safety.