USB rechargeable and easy to use: no longer need to buy and replace batteries for your luminous Doudou, just use the standard USB port on your computer or mobile phone charger. Press the button in the middle of the LED light to turn it on/off. Different brightness levels: three types of brightness are available, strong light (lasts 10 hours), medium light (lasts 15 hours), low light (lasts 20 hours). Convenient to charge and wash: just pull the edge of the beanie and push the light inwards to separate them and wash the hat or charge the light. The 4 LED lights have a high-quality IP44 waterproof rating. Elasticity and universal size: This winter warm LED knitted hat fits most children, men, and women with different head sizes, with high elasticity. Suitable: It is the perfect flashlight for camping, parties, cycling, barbecues, car repairs, fishing, jogging, or walking dogs on cold winter evenings.