Operates on 3 pieces of button cell battery.<br />Durable， high impact， water resistant and rust resistant.<br />Chrome body with ultra bright， long life-span LED lamp.<br />Automatic sensor turns lamp on when wheel is in motion.<br />Increases nighttime and bad weather visibility for enhanced safely.<br />Installs on standard tire air stem valve of cars， motorcycles or bicycles.<br />When you stop about two minutes they will switch off to save battery power.<br />If you want to add that personal touch to your car， bike - lighting is one of the best ways.<br /><br />When it is dark and your wheels start to move， they automatically flash light up creating a solid disk of light that appears to hover above your wheels.<br /><br />Specification:<br /><br />Cap Diameter: 15mm<br />Color: Blue<br /><br />Package Included:<br /><br />2 X Blue Valve Lights<br />3 X Button Cell Battery