Fding Waterproof Mutil-color Mountain Bicycles Bike Wheel Spoke Light with Light & Shock Control 12 Changeing Patterns for Mt Bikes Ground Bike Dead Flying Bicycle BMX Equipped with Light sensor and Movement sensor;Flash only at Dark light and action and it won't work and save your power when not riding Blade type hot wheels & Durable material:Durable silicone and water resistant;High quality LED chips: 5050 SMD with life up to 100,000 hours Flash 12 different kinds of patterns,and changes every 4 seconds;The faster speed,the clearer and more complete result it shows No tools required, fast and easy installation.(P.S recommend 2 or 3 Spoke Lights One wheel is more suitable ) Powered by battery 2x CR2032 (included) Constant light for over 40 hours