Led Bicycle Bike Wheel Light Auto Open & Close Wheel Spoke Light String Features: - Automatic lighting - Motion sensing - turns on automatically when the bike moves and turns off when no motion for 1 minute - Light sensing - turns on at night when the bike move - 2-meter light string - fits most bike wheel - No speed limit for starting up - Flash light mode - Make your riding visible and safe at night - Fast and easy installation - no tool required Specifications: - Overall Dimension: 2-3/4"L x 1-2/5"W x 4/5"H (L7cm x W3.5cm x H2cm) - Power Supply: 2x 1.5V AA Battery Package Contents: - 1x LED Light String (for 1 Wheel) - 1x Battery Compartment - 1 Set of Screws Notice: - AA battery is not included. - Before purchasing, please measure the circumference of your bike wheel and the circumference should no more than 2 meters. (Our light string is 2 meters long.). Automatic lighting Motion sensing - turns on automatically when the bike moves and turns off when no motion for 1 minute Light sensing - turns on at night when the bike move 2-meter light string - fits most bike wheel; No speed limit; Flash light mode Powered by 2 AA batteries