Come and see our amazing products. This hat is made of 100% cotton material with high quality LED Light strip. No heat, No Radiation. It is very safe and comfortable to wear. You can freely adjust the size for a better fit via the Nylon fastening on the back of the hat. "on/off" switch is concealed in the brim. There is a small dot sticker outside to notify you where the switch is. This cool and stylish luminous hat has four modes: Fast Flash, Slow Flash, Steady Bright and Off, you can switch freely by pressing the switch.The led glowing hat is equipped with 2 X CR2032 button batteries which can last for about 72 hours. The battery is replaceable. We also provide 2 extra batteries to extend its service life. It can be washed by hand with cold water, but the battery pack and line must be taken off before washing. Pls confirm further with us if any query about packing info, inventory status and time schedule.