Parameter:Type:WK-001Three fastener batteries.Can light 3-4 hours standingCondition : 100% Brand NewDimension: OVERALL SIZE: 9 cm， Bulb SIZE: 5.5 cm x 3 cm.Function:In night， it will falsh mysterious， just a very cool gift.Use Method:Press the key.Look at this key chain，it must be take your attention.This bulb key-chain only use three batteries and a LED.In the night，it'll flash 7 colors light，if you press the top of bulb.Package including:1x bulb keychain