Product pull up the straw・ the bottle will be lit・ the straw can adjust the brightness・ the higher the straw pulled・ the light on the brighter; Sucker pushed to the bottom of the bottle・ the light goes out.Good night lights apply to the bedroom・ outdoor camping・ walking at night lighting.Good night lights are good gifts for children.The first use to be full of more than 5 hours・ can be used for 4 hours・ if the use of brightness is not enough・ the need for timely charging・ indicating red light charging・ charging is off.